Britain accused Russia of "conduct not worthy of a great country" after what it called a campaign of intimidation by security services forced its cultural centres in two Russian cities to halt operations.

The British Council has been involved in an escalating dispute with Moscow over the legality of its Russian branches, part of a wider diplomatic argument over the murder in 2006 of a former Russian agent in Britain.

The British Council said it would suspend its work in St Petersburg and Yekaterinburg after Russian staff were summoned for interviews by the Federal Security Service (FSB) domestic intelligence agency, the main successor to the Soviet-era KGB.

British Foreign Secretary David Miliband said Russia's behaviour towards the British Council was "reprehensible, not worthy of a great country."

"Russia's actions therefore raise serious questions about her observance of international law, as well as about the standards of behaviour she is prepared to adopt towards her own citizens," Miliband said.

The European Union and United States expressed regret at the actions taken by Russia against British Council staff.

"The EU deeply regrets in particular the harassment of British Council staff, as well as the administrative and other measures announced by the Russian authorities," the EU's Slovenian presidency said in a statement.

Britain and Russia, linked in trade and investment worth billions of dollars a year, have been at odds since the 2006 murder of Alexander Litvinenko, who was poisoned in London with a rare radioactive material.

Each country expelled four diplomats in the spat after Moscow refused to extradite Russian businessman Andrei Lugovoy to face trial for the murder. He denies any role in the death, which has soured diplomatic ties.