He had been able to complete his accountancy qualification while interned and founded his own company, later known as Corvin & Co.[1] In 1926, he stood down from his IRA positions, to focus on his business interests.
[1] From the 1930s, he began supporting Fianna Fáil,[8] and later in the decade, he was a leading figure in the Northern Council for Unity, a short-lived split from the Nationalist Party.
[9] Corvin served as Eamon Donnelly's election agent in his campaign for Belfast Falls at a 1942 by-election to the Northern Ireland House of Commons.
[1] Donnelly won the seat, and his supporters then nominated Corvin for the British House of Commons at the 1943 Belfast West by-election, although the IRA repudiated his candidacy.
[5] Despite this, he remained close to some IRA members, and during World War II, he organised the Green Cross Fund to assist the families of republican internees.