Russia announced putative measures against Britain's cultural offices on Monday as they came back to work from holiday break, defying Russian orders to shut down.

The Russian Foreign Ministry called Britain's move a "deliberate provocation," in spiralling bilateral relations since the 2006 poisoning in London of former Russian spy turned dissident Alexander Litvinenko.

Britain has ignored Russian directives, which its ambassador said were counter to international law.

Russia cited a 1963 Vienna Convention on consular activities to order the closure in December of the British government's 15 regional offices including those in St Petersburg and Yekaterinenburg, where staff showed up as usual Monday.

"Considering that our calls have not been heeded, the Russian side is forced exert pressure through a series of administrative and legal measures," the Foreign Ministry said on its website.

Russia declared it would refuse visa to new council employs and demand back taxes from the organization.

It further threatened "additional measures concerning the British Council office in Moscow," embroiling the cultural organization's main office that had hitherto been exempt from the dispute.

Anglo-Russian relations sunk to new Cold War lows after Moscow refused to extradite an ex-KGB bodyguard suspected of murdering Litvinenko, culminating in the tit-for-tat expulsions of diplomats last year.

When the new row erupted, Foreign Minster Sergei Lavrov said Russia had suspend drafting the new cooperation agreement that constitutes the muddy legal basis for the organisation's operations, "as retaliation for the expelling of Russian diplomats from London."

British Ambassador Anthony Breton, who has been vilified by pro-Putin groups in recent months, was summoned to the Foreign Ministry on Monday for a confrontation with its deputy Vladimir Titov.

"The British Council is working entirely legally, and will therefore continue to work. Any Russian action against it would be a breach of international law," Brenton told reporters after his meeting with Titov.

The conflict over the council's legal status has churned since 1994. The organization sees itself as the cultural arm of the British Embassy and is not registered as an non-governmental organization under new Russian laws.

"We expect our British partners to stop ignoring obvious facts and refrain from a line of further confrontation that is fraught with the most negative consequences for Russian-British relations," the Foreign Ministry emphasized Monday.

In response to accusations by British government officials Monday, head of Russia's Committee on International Affairs Konstatin Kosachyov said, "I know precisely that claims on the British Council are juridical and financial."

"They are not related in any way to the latest complications in the Russian-British relations, even though these complexities have brought this situation to a climax," he was quoted by Interfax news agency as saying. d