Ill-health, he said, rather than the recession, was to blame; Sir Hugh had a cancer operation several years ago.
As well as losing an Old Master gallery, the art world is losing one of its most tireless campaigners. Sir Hugh has devoted almost half a century to heritage causes - from saving innumerable treasures for the nation to being one of the most vociferous opponents of museum admission charges.
Graham Greene, chairman of the Museums and Galleries Commission, the Government's main advisers on museum matters, was among many who paid tribute to him yesterday. 'The nation owes him a lot,' he said.
Sir Hugh cites two of his most satisfying achievements as seeing the 'admission free' notice outside the British Museum, and being instrumental in acquiring Hudson's portrait of Handel in the National Portrait Gallery, for which he organised fund-raising concerts and persuaded a friend to loan the necessary pounds 10,000.
Hundreds of paintings in the National Portrait galleries of England and Scotland, in particular, were acquired with his help. The National and Tate galleries also benefited. As a dealer, his understanding of the market has been invaluable: he advised on valuation and bid on their behalf. Yet, he never benefited financially - he always waived a fee.
Although Sir Hugh's two sons have been working as Leggatt Brothers sixth-generation dealers, they felt that borrowing pounds 8-pounds 10m to buy pictures was too much of a risk in a recession.
Sir Hugh said: 'When I joined the business in 1946 . . . it was a cottage industry. Now it's very big business. It's nowhere near as pleasant. There's so much money at stake. So many people carping and so much criticism . . . It used to be very gentlemanly . . . now it's a harsh business.'