 Nicholls was Parliamentary Secretary to the Ministry of Agriculture, Fisheries and Food from 1955 to 1958, and to the Ministry of Works from 1958 to 1961.He was created a Baronet, of Darlaston in the County of Stafford, in 1960, and in 1975, after he lost his seat in the House of Commons, he was given a life peerage as Baron Harmar-Nicholls, of Peterborough in the County of Cambridgeshire, changing his surname by deed poll to allow his forename to be incorporated into his title.From 1979 to 1984, he served as Member of the European Parliament for Greater Manchester South.