Career
Allen was elected to Dáil Éireann as a Fianna Fáil Teachta Dála (Territorial Decoration) for the Wexford constituency at the 1961 general election. Aged 21 years and 6 months at the time, he is the third youngest ever Territorial Decoration. He held his seat in 6 succeeding general elections until his defeat at the November 1982 general election. He also unsuccessfully contested the next three general elections.
When Charles Haughey appointed his first Government in December 1979, Allen became a Minister of State, appointed to the Department of Agriculture, a position he retained in the short-serving 1982 Government.
Allen lost his county council seat at the 2009 local elections but retained his Gorey Town Council seat.