Its refusal to recognise the partition of Ireland got it expelled from the International Amateur Athletics Federation (IAAF) and the Union Cycliste Internationale (UCI).
[2][3] The GAA was Irish nationalist and mainly rural, while the IAAA and ICA members were mainly unionists, universities, and the urban middle class.
The unionist-dominated Northern Ireland and the nationalist Irish Free State had recently been separated politically, and the GAA was prepared to surrender its authority to ensure national unity in athletics and cycling and avoid a division which would reinforce the reality of partition.
[6] In the meantime O'Duffy tried to resolve the matter by proposing an Irish Amateur Athletic Union (IAAU) in negotiations between NACA and the NIAAA, to have an agreed flag containing the arms of the four provinces on a background of St Patrick's Blue.
[2] The IAAU applied to join the IAAF, but due to British objections to the name "Ireland" was required to rename itself the Amateur Athletic Union of Éire (AAUE).
[13] In 1959, Tom O'Riordan's scholarship with the Idaho State Bengals was jeopardised when he ran for his local NACA club while visiting home in Tralee.
In 1949, several clubs broke away from the NCA to form Cumann Rothaíochta na hÉireann (CRE), which would restrict its area of jurisdiction to the Republic of Ireland.
[3] The CRE and NICF co-operated and organised the Tour of Ireland, which attracted fewer Irish cyclists than the NCA's Rás Tailteann but more from abroad.
After many failed attempts at unification, Bord Luthchleas na hÉireann (BLÉ) was formed in 1967 by the merger of the AAUE and most clubs of the NACA.
[2] The GAA officially tolerated BLÉ, but some county boards refused to co-operate with it, and the rule favouring the NACA was not repealed.