Tremayne, who was returned unopposed for the county for the fifth time in 1820, with his Whig father-in-law Sir William Lemon, had numerous family connections across the Cornish political spectrum, including the Tory 1st Baron De Dunstanville and the prominent reformer John Colman Rashleigh. He declared that he adhered to the same ‘independent’ principles on which he had first been elected, and in the past he had often voted with the Whig opposition to Lord Liverpool’s ministry, before associating himself briefly with the Grenvillites. A remark to his father in 1818, that he ‘abhorred’ Catholic emancipation and parliamentary reform, betrayed definite Tory leanings, and he had supported the government’s repressive legislation in late 1819.
He continued to attend regularly and speak occasionally, while serving on many select committees; Thomas Grenville† described him as being ‘in the highest class of honourable, independent and effective Members’.
He was granted ten days’ leave on account of family illness, 22 Apr., but returned to present a Cornish petition for relief from agricultural distress, 29 Apr. 1822.
He divided against repeal of the Foreign Enlistment Act, 16 Apr., reform in Scotland, 2 June, and inquiry into delays in chancery, 5 June 1823. He voted with the minority to introduce trial by jury in New South Wales, 7 July 1823. He described the prorogation of Parliament that month as ‘the flattest ... I ever witnessed’.
In September 1827, after the formation of Lord Goderich’s coalition ministry, Tremayne wrote to a friend that ‘the Whigs have opened themselves most terribly, and they catch it most roundly in every quarter’, although their only mistake in his opinion was to make their objection to the appointment of John Herries* as chancellor of the exchequer ‘so public a point’. He found it ‘quite ridiculous to witness the feeling that exists that the Protestant church is considerably more secure’ because of Herries’s presence.
