The peer was part of the famous construction dynasty founded by his grandfather, Sir Robert.
He was made a director of the family firm at 21.
He then went on to make a fortune of his own as a property developer in Australia, before turning to politics in 1975 when he became an aide to Prime Minister Margaret Thatcher.
He became one of her closest advisers and Conservative Party treasurer throughout her period in office, from 1979 to 1990.
She made him a life peer, Baron McAlpine of West Green in Hampshire, in 1984.