Russia's plan to close regional offices of the British government's cultural arm is ?totally unacceptable?, Prime Minister Gordon Brown said on Thursday, demanding Moscow reverse its decision.

?This is totally unacceptable ... We wish this action to be desisted from immediately,? Brown told a parliamentary committee, adding that Russia must not put at risk the welfare of British Council staff.

Relations between the two countries are at their worst since the Cold War, soured by mutual espionage allegations, the murder of former Russian intelligence official Andrei Litvinenko in London last year, tit-for-tat expulsions of diplomats and a revival of Russian long-range bomber patrols. Russia's Foreign Ministry said on Wednesday it would temporarily ban the British Council in all regions of the country except Moscow from Jan. 1, saying three regional cultural offices had not been legally registered.

Britain denounced the decision as illegal. ?The British Council's presence in Russia is entirely consistent with international law,? Foreign Secretary David Miliband said in a statement. ?For Russia to carry out its threat would therefore constitute a serious attack against the legitimate cultural agent of the British government; would show a disregard for the rule of law and would only damage Russia's reputation around the world.?

Miliband said Britain was discussing the implications of Russia's threat with partners in the European Union and the Group of Seven rich countries and was grateful to the EU for expressing its concern to Russia about the situation.

The British Council operates as a not-for-profit charity run as a royal charter by the British government in 109 countries, teaching English, providing business contacts and administering academic tests for students who wish to study in Britain.

Sophie WALKER