Russian authorities have halted a major London exhibition of French and Russian art over claims Britain has failed to guarantee the paintings' return.
The Hermitage had planned to loan Pablo Picasso's Dryad
Russia's culture agency said the show could not go ahead unless the British government took further steps to ensure legal protection for the paintings.
British Culture Secretary James Purnell told BBC Radio 4 he would push through legislation offering better guarantees.
The exhibition had been due to open at the Royal Academy of Arts in January.
Some of the art of the From Russia: French and Russian Master Paintings exhibition had been taken from private collections after the 1917 revolution.
It is thought some of the 120 works of art - which include paintings by Matisse and Van Gogh and other renowned Impressionist and Post-Impressionist works - could be seized to settle private legal claims related to the paintings.
Purnell said he had assured Russia in a letter earlier this month that the artworks were protected under the State Immunity Act of 1978.
But Russia's Federal Culture and Cinematography Agency, Roskultura, said it had not received adequate legal guarantees.
Roskultura spokeswoman Natalya Uvarova said: "We have not received a state guarantee from the United Kingdom.
"We have only a guarantee from the culture ministry, which is not enough for the exhibition at such a level. This is the usual practice."
As a result, Mr Purnell said he would bring forward the implementation of the Tribunal Courts and Enforcement Bill 2007, part of which contains the assurances the Russians are seeking.
"Their letter says that that's what they require and that's what we will be doing because we attach such importance to cultural relations as a way of furthering relations between our countries," he told the BBC's World At One programme.
"Because this is such an important exhibition we are prepared to go the extra mile," he added.
The bill, which was passed earlier this year, will be put through parliament when MPs return on 7 January.
Russian officials have yet to respond to the announcement.
The exhibition, which includes works from the State Hermitage Museum in St Petersburg and Moscow's Pushkin Fine Arts Museum, is currently in Dusseldorf, Germany.
The cancellation comes at a time when relations between Russia and the UK are particularly strained.
Relations between the two countries have been strained recently
"Both the Russian and the British governments deny that this is part of the bigger political disagreement between them," said BBC diplomatic correspondent Bridget Kendall, "but it's hard not to see it in this context when the list of disputed areas between the two sides is so great."
Relations between the two have worsened since former KGB agent Alexander Litvinenko was poisoned in London last year.
In July, Britain expelled four Russian diplomats over Moscow's refusal to extradite a key suspect in the murder.
Russia followed by expelling four British diplomats and, last week, ordered the British Council to close down its two offices outside Moscow by the beginning of January.
The Russian foreign ministry said the council, which promotes British culture abroad, was operating illegally. The British Prime Minister's office denied the claims.
The director of the Hermitage Museum in St Petersburg, Mikhail Piotrovsky, told the BBC politics and culture should not be mixed.
"Remember that Russia and Britain regularly have these flashpoints which come and go," he said.
"Culture should function independently and we have never suffered such a connection.
"We have many projects with Britain. Political relationships change but I sincerely hope that nobody will use this for a fleeting political gesture," he added.