He served as a Teachta Dála (TD) for the Longford–Westmeath from 1965 to 1987, a Member of the European Parliament (MEP) for the Oireachtas from 1973 to 1979 and a Senator for the Administrative Panel from 1954 to 1965.
[3] L'Estrange was an unsuccessful Clann na Talmhan candidate for Dáil Éireann at the 1944 general election.
[4] After the 1981 general election, a Fine Gael–Labour Party coalition was returned to office in the 22nd Dáil under Taoiseach Garret FitzGerald.
L'Estrange was appointed Minister of State at the Department of the Taoiseach, a position which included the role of Chief Whip.
[3] The then Taoiseach, John Bruton, spoke of a man who "could speak strongly and from a deep conviction and at the same time hold no personal malice towards any of the victims of his eloquence".