In 1703, Erle became MP for Cork City in the Irish Parliament and held this seat until 1713. He was given command of a newly raised regiment of dragoons in June 1704 and did not vote for the Tack on 28 November 1704. In 1705, Erle was appointed Lieutenant-General of the Ordnance, a post which he held until 1712. He was also returned again as MP for Wareham at the 1705 English general election. Erle supported the Court choice of Speaker on 25 October 1705 and was named to the drafting committee on the mutiny bill on 23 January 1706. He voted with the government over the regency bill on 18 February 1706. Erle managed the mutiny bill through the House, and chaired the committee of the whole on 6 March 1706.