LONDON — Conservative politician Norman Tebbit, a key ally of Prime Minister Margaret Thatcher in her free-market transformation of Britain, has died at the age of 94, his family said Tuesday. Tebbit’s son William said he died peacefully at home late Monday. No cause was given.

He was a potential prime minister until he left high office to care for his wife, who was seriously hurt in a bombing by the Irish Republican Army.

Thirty years later he did, as Thatcher’s secretary of state for employment. Tebbit’s 1982 Employment Act avenged the unions’ defeat of Heath. Union rights were weakened, never to be restored, and those of employers emboldened. It was a significant contribution to Thatcherism’s ledger.