The father-of-three passed away in his sleep this morning at his Sussex home, his family said.

Lord Healey, who was in Number 11 between 1974 and 1979, had to deal with the economic consequences of a five-fold increase in oil prices in 1973 to 1974.

He also grappled with the demands of powerful trade union leaders as well as the IMF crisis of 1976.

Friends said he was proud of his record as defence secretary under Harold Wilson in the 1960s, and is credited with not sending British troops to Vietnam.

Lord Healey, often described as "the best prime minister we never had", was a major in the Second World War.

He served in the Royal Engineers in North Africa and Italy, and was beach master during the Anzio landings.

Labour leader Jeremy Corbyn was one of the first politicians to pay tribute, saying: "Denis Healey was a Labour giant whose record of service to party and country stands as his testament. All our thoughts are with his family."

Prime Minister David Cameron called him a "huge figure of post-war politics."

"By all accounts he was a hugely entertaining man personally - and author of tremendously readable and informative books. A great man and a genuine public servant has left us," he said.

Chancellor George Osborne described him as a "giant of the Labour movement" who had been in office "in the most difficult circumstances."

Shadow foreign secretary Hilary Benn, whose father Tony unsuccessfully ran against Lord Healey for the party's deputy leadership, said: "Very sorry to hear that Denis Healey has died. All our thoughts are with his family on their loss."

Lord Healey stood unsuccessfully for election in 1945 and eventually entered the Commons as MP for Leeds South East in 1952.