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
William Mainwaring caused some amusement when they appealed to Labour to withdraw their candidate to stop splitting the working-class vote. Mainwaring succeeded in increasing his majority to 8,433. In the new Parliament, Mainwaring won sixth place on the ballot to introduce a Private Member's Bill and chose to try to make employers liable for injuries to workmen caused by the negligence of fellow workmen. When debated, a Conservative MP moved to reject the Bill, and the Government declared their opposition; the Bill was defeated by 146 to 85. In the next session, Mainwaring won again, this time in first place; he introduced