Haw was born in Woodford Green, Redbridge, a twin and the eldest of five. He grew up in neighbouring Barking and in Whitstable, Kent. His father, who had been one of the first British soldiers to enter the Bergen-Belsen concentration camp, worked in a betting office. He committed suicide by gassing himself when Haw was 13. Haw was apprenticed to a boat-builder from the age of 16 and then entered the Merchant Navy as a deckhand.