Under the Redistribution of Seats (Ireland) Act 1918, NUI was enfranchised as a new university constituency and continued to be entitled to be represented by one Member of Parliament in the British House of Commons until the dissolution of Parliament on 26 October 1922, shortly before the Irish Free State became a dominion outside the United Kingdom on 6 December 1922.
Eoin MacNeill was elected (and also for Londonderry City) standing for Sinn Féin and therefore did not take his seat in Westminster, instead serving as a member of the first Dáil Éireann.
At the last meeting of the First Dáil on 10 May 1921, it passed a motion, the first three parts of which expressed this constitutional position.
[1] No voting occurred in Southern Ireland as all the seats were filled by unopposed returns.
Except for Dublin University all constituencies outside Northern Ireland elected Sinn Féin TDs.
From the Electoral Act 1923 the Irish Free State defined its own Dáil constituencies.
This Act abolished plural voting for University constituencies and enfranchised women on the same terms as men.
The qualifications for an elector to be registered as a university voter were set out in Section 1(2)(c) of the 1923 Act.
23) Act 1936 repealed provisions of the Constitution of the Irish Free State providing for University representation in Dáil Éireann, with effect from the next dissolution of the Oireachtas which took place on 14 June 1937.
The seat left vacant by Conor Maguire in 1936 on his appointment to the High Court was not filled.
Sinn Féin refused to recognise the Southern Ireland House of Commons and took their seats as TDs in the Second Dáil.
In common with other Sinn Féin MPs, Eoin MacNeill abstained from Westminster and took his seat as a TD in the First Dáil.