During his parliamentary career, Waddington worked in government as Chief Whip, then as Home Secretary and finally as Leader of the House of Lords.

[2] Waddington failed to adequately defend Stefan Kiszko, a civil servant accused of the murder of Lesley Molseed, at Leeds Crown Court in July 1976 in what would become one of the most notorious miscarriages of justice in British legal history.

Kiszko served 16 years in prison, receiving frequent violent attacks for being a "child killer", after wrongly being found guilty.

[3] He was first elected to Parliament at the 1968 Nelson and Colne by-election, caused by the death of Labour MP Sydney Silverman.

He was re-elected there in 1970 and in February 1974, but lost his seat at the October 1974 general election by a margin of 669 votes to Labour's Doug Hoyle.

[2] Waddington was returned to Parliament for Clitheroe at a by-election in March 1979, and was subsequently elected for the broadly similar Ribble Valley constituency in 1983.