 He did not contest the 1964 election, when Labour returned to government under Harold Wilson, but was created a life peer on 14 May 1965, as Baron Winterbottom, "of Clopton in the County of Northampton".After Labour's victory at the 1966 general election, he joined the Labour Government, serving as Under-Secretary of State for the Navy until 1967, as Parliamentary Secretary to the Ministry of Public Building and Works from 1967 to 1968 and finally as Under-Secretary of State for the Air Force from 1968 until the government's defeat at the 1970 general election.In 1981 he joined the Social Democratic Party (SDP) as a founder member.