Sean MacBride, Senior Counsel and T. J. Conolly, Senior Counsel (with them H. R. McWilliam ), of counsel assigned by the Court:—

Five matters arise on this Bill, any one of which, we submit, renders it repugnant to the Constitution. The first three matters did not arise, and could not have arisen, in  O'Donovan v. Attorney General ⁽¹⁾, the last two were considered in that case, but the Oireachtas, notwithstanding the guidance given to it by Budd J. in  O'Donovan's Case ⁽¹⁾, none the less failed to comply with the provisions laid down in Art. 16, clause 2, paras. 3 and 4, as governing the allocation of members of Dáil Éireann éireann to constituencies.

First, Art. 16, clause 2, para. 4, prescribes that "the Oireachtas shall revise the constituencies at least once in every twelve years." The revision effected by this Bill was made over thirteen years after the last effective electoral revision, namely, that carried out by the Electoral (Amendment) Act, 1947, which became law on the 27th November, 1947. While the delay in effective revision was rendered inevitable by the fact that the revision made by the Act of 1959, and declared ineffective, was made immediately before

Secondly, it is now apparent that the total number of members in Dáil Éireann éireann has been fixed at more than one member for each twenty thousand of the population, contrary to Art. 16, clause 2, para. 2. The figure of 144 members fixed for the Dáil by the Act of 1959 which was fixed on the basis of the 1956 census returns, showing a total population of 2,898,264 in the State, has not been departed from in the present Bill, notwithstanding that the Annual Estimates furnished by the Central Statistics Office show that the estimated population of the State is April, 1960, was 2,834,000 (which would allow for a Dáil of, at most, 141 members), while, on the basis of the register of electors for 1961 and of the figure of 61 Dáil electors per 100 of population, the population would amount only to 2,757,801 (which would allow for a Dáil of, at most, 137 members). While these figures are admittedly less precise than the 1956 census figures, nevertheless one or other of these sets of figures ought to have been adopted by the Oireachtas, as affording a more accurate guide than the 1956 census figures to the exact population of the State at the time of the passing of the Bill.

A deliberate change of expression in one section of a statute from that used in an earlier section, must be takenprima facie to import a change of intention:  Ricket v.Directors, &c of Metropolitan Railway Co. ⁽¹⁾. The primary and natural meaning of the words of a statute or other authoritative document ought never to be extended by the Court "unless for a case amounting to a necessity, or approaching to it": per Lord Bramwell in  M'Cowan v.Baine ⁽²⁾. [They also referred to Maxwell on the Interpretation of Statutes, 1946 ed., pp. 14 and 324.] Accordingly, the reference in para. 3 of Art. 16, clause 2, to "the population of each constituency, as ascertained at the last preceding census," when contrasted with the absence of reference to the last preceding census in paras. 2 and 4 of that clause, indicates that the Oireachtas is bound by the figures of the last preceding census only in so far as it is required by para. 3 to seek to achieve parity of representation as between the various constituencies. The provisions of para. 4 qualify those of para. 3 to this extent: that, where a change in distribution of population sufficient to require a revision of constituencies is ascertained to have taken place in an intercensal period, the Oireachtas is bound to make such revision

Thirdly, it is submitted that the Bill under review contravenes Art. 16, clause 2, para. 3, of the Constitution in as much as it purports to determine the number of Dáil members per constituency by reference to the population of each constituency as ascertained at a census earlier than the last preceding census, which, it is submitted, in this context means the census taken in April, 1961. The provision in para. 4 that the constituencies are to be revised "with due regard to changes in distribution of the population"indicates that the intent of the Constitution was that, where the results of a recent census are on the verge of being ascertained, such revision ought to be deferred pending such ascertainment, rather than be made with reference to a more distant census.

Fourthly, the Oireachtas has not yet succeeded in complying with the requirement of Art. 16, clause 2, para. 3, that the ratio between the number of Dáil members for each constituency and its population, even on the basis of the 1956 census, should, as far as it is possible, be the same throughout the country: see the Irish text of the paragraph, which prescribes that the ratio between Dáil members and population in each constituency must be "ar cothrom, sa mhéid gur féidir é, ar fuaid na dúiche uile." Here, as the Irish and the English texts of the paragraph do not coincide ("gan [iad] . . . do bheith do réir a chéile": Art. 25, clause 5, para. 6), the Irish text of the paragraph must prevail. [They also referred to Art. 63]. This imposes a slightly more stringent obligation on the Oireachtas than does the English text, which requires parity of representation as between the constituencies merely "so far as it is practicable." While it is conceded that absolute mathematical parity of representation as between the constituencies is not possible, the paragraph requires as near an approach thereto as can reasonably be achieved. It is suggested that the degree of parity which should be required is that the population per Dáil member of each constituency should be not more than 500 above or below the national average. Here, taking the 1956 census figures as a basis throughout, out of a total of thirty-nine constituencies, nineteen have an average population per Dáil member deviating by more than 500 from the national average—eight above it and eleven below it; six

In particular, the two groups of adjoining constituencies consisting of the eight constituencies for the City and County of Dublin, and of the nine constituencies for the province of Connaught and the Counties of Clare and Limerick have each been allocated 34 Dáil members. The former group has a total population of 705,006, which gives it one Dáil member for each 20,735 of population, while the latter group has a total population of 664,278, which gives it one Dáil member for each 19,449 of population. It would have been not only physically possible, but administratively practicable, so to have allocated Dáil members to constituencies as to give the former group an extra Dáil member at the expense of the latter—when virtual mathematical parity of representation as between the two groups and a close correspondence between the ratio for each group and the national average would have been achieved. The provision of Art. 16, clause 2, para. 2, that the total number of members of Dáil Éireann éireann should not be fixed at less than one member for each thirty thousand, or at more than one member for each twenty thousand, of the population, appeared to envisage the original fixation of the membership of Dáil Éireann éireann on the basis of one member for each twenty-five thousand of the population, approximately. If this basis had been adhered to by the Oireachtas in enacting this Bill, it would have been a simple matter to remedy the disparity of ratio of Dáil members to population between Dublin and the West, by allocating another seat or two to Dublin without necessarily interfering with the Western constituencies. The administrative difficulties which might be created by such interference resulted from the action of the Oireachtas in providing that the Dáil should contain the maximum number of members constitutionally permissible, having regard to the 1956 census figures.

Fifthly, the Oireachtas, in purporting to revise the constituencies in this Bill has failed to have due regard to changes in distribution of the population as required by Art. 16, clause 2, para. 4. If the Court takes the view that the Oireachtas. in revising the constituencies pursuant to this

While the consideration of the constitutionality of Acts of the Oireachtas must be approached with a presumption in favour of such constitutionality (per Murnaghan J. in  National Union of Railwaymen and Others v. Sullivan and Others ⁽¹⁾,it is submitted that no such presumption operates in favour of a Bill referred by the President to this Court in pursuance of the provisions of Art. 26 of the Constitution, in as much as such reference of itself indicates that the President was aware of the possibility that such Bill, if signed by him and promulgated as a law, might later be found to be unconstitutional. This presumption of constitutionality is expressly related by this Court in  In re Art. 26 of the Constitution and the Offences Against the State (Amendment) Bill ⁽²⁾to "any particular law" which, it is submitted means an Act which has been signed by the President pursuant to Art. 13, clause 3, para 1, and promulgated by him pursuant to Art. 13, clause 3, para. 2, as distinct from a Bill which has merely been passed by the Oireachtas.

The necessity of rebutting such presumption of constitutionality arises only where it is sought to establish that a measure is repugnant to the Constitution by reason of some implied prohibition or repugnance:  In re Art. 26 of the Constitution and the Offences Against the State (Amendment) Bill , 1940 ⁽¹⁾;  In re Art. 26 of the Constitution and the School Attendance Bill , 1942 ⁽³⁾. Where, as here, it is sought to establish that a measure is repugnant to the Constitution by reason of the contravention of an express prohibition contained therein, the Court, in considering the measure, ought not to exercise any presumption in its favour.

The Attorney General (with him R. McGonigal, Senior Counsel , and Sean Butler ):—

The provisions of s. 5 of the Bill before the Court, relating to the outgoing Ceann Comhairle, are necessitated by the combined effects of Art. 16, clause 6, of the Constitution, which requires provision to be made by law to enable an

The provisions of Art. 16, clause 2, para. 4, of the Constitution, which require the Oireachtas to revise the constituencies"at least once in every twelve years" are directory, not mandatory. If, for any reason, the Oireachtas has failed to carry out such revision within the twelve-year period, its obligation under this paragraph of the Article is fulfilled by a revision as soon as reasonably possible after the expiration of the period. If this requirement were to be construed as mandatory, there could, on the next dissolution of Dáil Éireann éireann, be no constituencies in existence to which members of Dáil Éireann éireann could be elected.

"The last preceding census" to be considered in determining the ratio between the population of the respective constituencies and the number of Dáil members to be elected for each, pursuant to Art. 16, clause 2, para. 3, is still the census of 1956. The census of 1961 has not yet been taken, in as much as the counting of the population under such census has not yet been completed. The Irish version of the paragraph refers to "an daonáirimh is déanaí dá ndearnadh,", which might literally be translated "the last counting of the population which was made," the Irish word,"daonáirimh," involving the concept of counting. This indicates that the phrase, "the last preceding census," in the paragraph was intended to refer, in this context, to"the last preceding census which has been completed."Paragraphs 2, 3 and 4 of Art. 16, clause 2, ought to be read together as all being based on the determination of the population, both of the State as a whole and of the individual constituencies, in a particular way, specified only in para. 3. This construction finds support in the fact that the one of the three calculations described in the three paragraphs for which the most precise information possible is most essential is that described in para. 2, which involves the fixation of

The revision of the constituencies by reference to the proportion of electors to the total population in each could not be carried out in such a way as to comply with Art. 16, clause 2, para. 3, in view of the grave variation of that proportion as between the constituencies, ranging from 53 per cent. in Dublin County to 66 per cent. in West Donegal.

The provision in Art. 16, clause 2, para. 3, that the ratio of members of the Dáil for each constituency to the population of that constituency shall be the same throughout the State "so far as it is practicable," is made in recognition of the necessity of some departure from absolute mathematical equality. It is the function of the Oireachtas to determine the extent to which such departure is necessary and the Court, in considering whether or not the Oireachtas has exceeded such function, is bound to have regard to the law as it existed at the time of the enactment of the Constitution. [He referred to  Melling v. Ó Mathghamhna ó mathghamhna (unreported) and to In re Article 26 of the Constitution and the Offences Against the State (Amendment) Bill , 1940 ⁽¹⁾]. The Court is, therefore, bound to consider the operation of the Electoral Acts of 1923 and of 1935, both accepted as implementing the Constitution of 1922, and therefore, it must be assumed, accepted by those who framed the Constitution of 1937 as indicating the extent to which absolute mathematical parity might be departed from. The total variation of persons per member between the most highly represented and the least highly represented constituencies under the Act of 1923 was 3,708, the maximum divergence from the national average being 2,458. Under the Act of 1935 the corresponding figures were 4,411 and 2,923. It is submitted that, if departures to that extent from absolute mathematical parity could be sanctioned as being as close approximations to absolute mathematical parity as were practicable, the much smaller departures from parity contained in the Bill under review must be regarded as permissible under the provisions of Art. 16, clause 2, para. 3. It is conceded that,

Sean MacBride, Senior Counsel , in reply:—

The issue, as between our construction of the three relevant paragraphs of Art. 16, clause 2, and that of the Attorney General is based in essence on the construction to be placed on para. 4. Our submission is that para. 3 is designed to deal with a revision of constituencies made immediately after the completion of a census, and para. 4 with a revision made, either by the will of the Oireachtas or by the compulsion of para. 2 in the light of the most recent population figures, in an intercensal period. The Attorney General, on the other hand, construes both para. 3 and para. 4 as deriving effect from a completed census. While both constructions enable effect to be given to paras. 3 and 4 without adding words to the paragraphs or taking words therefrom, it is submitted that, once the population is found to have passed beyond the maximum or minimum number of persons per member of Dáil Éireann éireann prescribed by para. 2, the Oireachtas then has no option but to revise the constituencies forthwith; otherwise, para. 2 can be regarded only as surplusage.

In determining what the total number of Dáil members should be in relation to the total population of the State, the Oireachtas ought to have relied on the more accurate, if not precise, figures provided either by the current electoral lists or by the most recent population estimates, rather than on the precise, but no longer accurate, figures provided by the census of 1956. The fixing of the total membership of Dáil Éireann éireann and the revision of the constituencies by reference to an out-of-date census can be justified only by the importation of the phrase, "as ascertained at the last preceding census," into paras. 2 and 4, as well as into para. 3, of clause 2 of Art. 16. This phrase must be deemed to have been omitted designedly from those two paragraphs, in the light of the rule of construction, expressio unius rei est exclusio alterius.

The degree of elasticity with which para. 3 may be construed cannot be extended in the manner sought by the