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Two of the most important paintings in Britain could be lost to the nation unless £100 million is found to keep them. The paintings, by the Renaissance master Titian, are believed to be worth £300 million on the open market, but are offered at a discount to the nation by the Duke of Sutherland.

He has set a deadline of New Year’s Eve to agree the £50 million purchase of Diana & Actaeon, with a second £50 million asked for Diana & Callisto in four years’ time.

Alistair Darling, the Chancellor, already under pressure to help home-owners, drivers, poorer families and athletes, was being urged last night to find enough money for the paintings.

Times Archive, 1933: The Bridgewater Titians

'Actaeon' is the most complete and satisfying of the paintings, as it is the one that has suffered least by time

• The conservation of pictures

• Picture: The vapour chamber used by Mr Kennedy North for the conservation of Titian's painting, Diana and Actaeon

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The Times understands that Andy Burnham, the Culture Secretary, has asked the Treasury for an emergency grant of £10 million to £20 million to go alongside money raised by the National Heritage Memorial Fund and private donations. It would be the first such grant since 1972, when the Treasury gave the National Gallery £381,500 to help to buy another Titian,The Death of Actaeon, for £1.8 million.

The paintings are the crowning glories of the celebrated Bridgewater collection of 27 Old Master paintings owned by the Duke and on display at the National Gallery of Scotland.

The directors of the National Galleries of Scotland and the National Gallery in London say that the £100 million offer is a “stupendous deal”. If the campaign is successful the Duke will extend the loan of the remaining paintings in the collection by 21 years. If not, he will sell some of the collection, though not necessarily the two Titians. He wants to broaden his investment portfolio, which has been skewed by inflation in the art market.

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