Allen took advantage of his local connexions to cultivate an interest at Bridgwater. He became a member of the corporation, and in 1768 contested the borough against the powerful Poulett interest. In Parliament Allen voted regularly with Opposition. His only reported speech was on East India affairs, 24 Mar. 1773. In 1774 he was returned unopposed. The Public Ledger wrote of him in 1779: ‘Seems to be a fair, well-meaning man. Votes on each side conformably to his opinion, but generally in opposition.’ Charles James Fox wrote to John Chubb, of Bridgwater, 8 Apr. 1780:
Allen died before 1792,
