For eight years after its partition from the rest of the island, Northern Ireland continued to share the system of proportional representation as used in the Free State. This retention was to the chagrin of many unionists who favoured a return to First Past the Post, in line with the rest of the UK. The long interval between the establishment of the Stormont government and the final reversion to FPTP was largely due to the Labour-led government in Westminster - Labour was known to be sympathetic to the Irish nationalist cause and the Ulster Unionist Party feared a ruling against their favour if they were to take the matter to the government.
When the system was changed in 1929, a redrawing of constituency boundaries had to be done. Rather than revert to the constituencies which existed between 1885 and and 1921, new - albeit vaguely similar - areas were created. The six counties of Northern Ireland held 30 seats before the change to PR in 1921. With this reversion came 22 extra seats, keeping the total number of seats at Stormont as it was at 52. As the revisions were carried out by the government - the UUP - they were wide open to allegations of fixing and bias. The government naturally denied these claims but opponants pointed for example to the division of Fermanagh - a majority nationalist county which for the entire lifetime of the Stormont House of Commons returned only one nationalist and two unionists.
These constituencies were altered only once in 1969, the same year the parliament was abolished. These alterations were minor: Queen's University lost its representation and four new seats were created in and around Belfast. Due to the obvious problems posed by the restrictiveness of First Past the Post, as well as constant accusations of gerrymandering, Northern Ireland would never again return to single-seat constituencies after the abolition in 1969.
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