Pollington, who had sat for the open and venal borough of Pontefract with one brief interruption since 1807, was returned there in second place in 1820. Although he had previously acted with the Whig opposition to Lord Liverpool’s ministry, he had exhibited a growing conservatism at the close of the 1818 Parliament. His changing political allegiance did not help endear him to Robert Peel*, who had a ‘particular dislike’ of him and found him ‘a most singular character with an apparent horror of truth’. Writing to his wife during a visit to Lord Hertford’s, Peel noted that Pollington had been ‘invited here to crow like a cock for the amusement of the party after dinner’.
In February 1830 he succeeded his father as 3rd earl of Mexborough, inheriting the Methley estate, £14,000, an unspecified amount in government stock and the residue of personalty which was sworn under £33,000.
Mexborough wrote to Peel in March 1835 requesting that he be given an English peerage, which he claimed George IV had wished to see conferred on his father; the application was refused.
