Returned on the family's electoral interest at Lewes in 1705, he provided a reliable Whig vote in the House of Commons, and a rather more sporadic attendance on the Board of Trade.

Unusually, three other candidates contested the election: the Whigs Thomas Fagg and his relative John Spence, and the Tory Nathaniel Trayton, steward of the Duke of Norfolk's estates in Sussex.

[1] In the 1710 election, Trayton, who had bought the manor of Southover nearby in 1709, again contested the seat, but was defeated by Pelham and his fellow Whig Peter Gott.

Through the influence of his half-cousin's son, the Whig grandee the Duke of Newcastle, he was able to exchange this for a seat as a Lord of Trade, worth £1,000 a year, under the First Stanhope–Sunderland ministry.

His only reported speech was made in 1720, against Sir Robert Walpole's motion to fix the rate for conversion of government securities to South Sea Company stock.