[2] As a magistrate he was active in local government as a district and county councillor and stood for the Westminster Parliament at the January 1910 general election as an Independent Nationalist in West Limerick, with the support of the All-for Ireland League, a non-sectarian alliance of nationalists and unionists, where he came within 70 votes of winning the seat in a close fought contest.

He was elected as Leas-Chathaoirleach to Lord Glenavy in 1925 and as Cathaoirleach (Chair) of the Senate in 1928, he was vigorous in defending constitutionalism in Irish life during a turbulent time and was engaged in a very high-profile contest with the President of the Executive Council Éamon de Valera in 1935 during the campaign to abolish the Seanad, in which he was assisted by his brother George C. Bennett, a Teachta Dála (TD) in Fine Gael and later Senator.

[2] Committed to the link between the United Kingdom and Ireland as equal members of the Commonwealth, he led an Irish delegation to the Empire Parliamentary Conference in 1935 where he dined with British Prime Minister Stanley Baldwin, attended receptions with the King George V and the Duke and the Duchess of York (the future King George VI and Queen Elizabeth) and negotiated with leaders of delegations from South Africa, Canada, Australia, New Zealand, the Indian Raj and many others as well as attending a Fleet Review and visiting many cities in the United Kingdom to promote the Irish Free State.

He became Chair of the Irish Agricultural Wholesale Society in 1945 remaining at its helm until his death in February 1962, after a lifetime of public service.

A keen huntsman, he remained active in the Country Limerick Foxhounds all his life, and enjoyed shooting, the cinema, horse racing and the Irish language.

In April 1923, he married Lila Hapell (died July 1976), daughter of William Alexander Happell, who had been in the Indian Civil Service.