William Mainwaring (English politician) Burdett. Mainwaring had previously resisted Burdett's calls for an inquiry into prison abuses, particularly at Coldbath Fields Prison. Mainwaring was defeated by Burdett but the election was declared void in 1804 and in the following contest William's son George Boulton Mainwaring was elected. The result was reversed in favour of Burdett in 1805 and the back in favour of Mainwaring Junior in 1806. Mainwaring did not contest the 1807 election and Burdett was not elected. He died in 1821, leaving one son. William Mainwaring (English politician) William Mainwaring (6 Oct 1735 – 28 February 1821) was the MP for Middlesex
Sam Mainwaring life. Mainwaring was raised by his family as a Unitarian. He developed into a quiet yet persuasive public speaker and a tireless worker for activities which he believed important. Mainwaring was a member of the Amalgamated Engineering Union. Late in the 1870s, Mainwaring joined the East London Labour Emancipation League and was an early member of the Social Democratic Federation. However, this group proved to be a disappointment, failing to garner support of an appreciable section of the working class and was believed by many members to overly dominated by the intellectual pretensions and nationalist political views of its patriarch