 Between 1974 and 1981, Wrigglesworth was Labour Member of Parliament for Thornaby on Teesside.He was one of the founder members of the Social Democratic Party (SDP) in 1981 and was subsequently elected SDP Member for Stockton South from 1983 until 1987, when he lost his seat.In 1988, he became the first president of the Liberal Democrats and was chairman of the Liberal Democrat Trustees until February 2012, when he became national treasurer.