Williams, a partner in his father’s bank in Birchin Lane, became an alderman of London, representing Cornhill ward, before he was thirty.
Williams had to find another seat in 1807. Sir Christopher Hawkins offered him one for Grampound for £4,000, but the poll went against him. The election was voided and Williams came in after another contest, only to be unseated on petition seven weeks later. He became a member of the Pitt Club. In January 1809 he was defeated by a Whig in a by-election at St. Albans, but soon afterwards came in for an Irish seat placed at Treasury disposal by Lord Desart. He stood by Perceval’s ministry on the Scheldt question, 23, 26 Jan., 5, 30 Mar. 1810, and was listed ‘against the Opposition’ by the Whigs. He may have spoken on 15 June 1809 against Burdett’s motion for parliamentary reform
In 1812 Williams succeeded to his father’s seat for Dorchester. He was listed a Treasury supporter. He voted against Catholic relief, 13 and 24 May 1813, and also in 1816 and 1817. He appears to have voted against agricultural protection, 3 and 10 Mar. 1815, and against the renewal of the property tax, 18 Mar. 1816, but in other respects rallied to government: on the army estimates, 6 and 8 Mar. 1816; on the civil list, 8 May 1815, 6 and 24 May 1816; on the lords of the Admiralty, 25 Feb., and for the suspension of habeas corpus, 23 June 1817. In November of that year he was described as ‘a firm friend’ of administration.
