Despite his narrow majority and the belief that he was the most vulnerable of the Liberal MPs, Penhaligon kept his seat with a much larger majority (8,708) in the 1979 general election. Against the Conservative government, he strongly opposed nuclear power. Against the majority of Liberal Party members he strongly supported NATO and nuclear weapons, describing a separate European non-nuclear defence as 'akin to a behaving like a virgin in a brothel', although he supported demands for 'dual key control' of United States cruise missiles based in Britain.