What British Prime Minister did Wilberforce serve under who became party leader in 1975?
Wilberforce (cat): Wilberforce was a cat who lived at 10 Downing Street between 1973 and 1986 and served under four British Prime Ministers: Edward Heath, Harold Wilson, Jim Callaghan and Margaret Thatcher. Edward Heath:  He became an embittered opponent of Margaret Thatcher, who supplanted him as party leader in 1975.
Margaret Thatcher