Russia has given its most explicit warning to date of the kind of punishment that Ukraine can expect if the former Soviet republic continues along the path towards membership of Nato, according to The Independent.

"The expansion of Nato is seen in Russia as a hostile action. We will never accept this. We cannot block expansion of Nato but we can take measures to ensure our security," the Russian ambassador to Britain, Yuri Fedotov, said in an interview.

Ukraine`s pro-Western government of President Viktor Yushchenko is campaigning to take his country into the EU and Nato. Russia`s fierce opposition to Nato expansion on its borders has prompted fears of a possible military conflict with Ukraine that would dwarf the war in Georgia.

The envoy pointed out that Ukraine – a country of 46 million people – and neighbouring Russia were tightly linked historically, culturally and economically. "The borders are virtually open," he said.

"Should this country become a Nato member... it means that we should take some measures to protect ourselves, and this may have an impact on this multitude of relations, ties and connections. It might not only affect trade and economic relations but also people-to-people contacts," he said. The ambassador would not go into further details but said: "I hope that common sense will prevail and that Nato countries will think twice."

Mr Yushchenko`s own government is divided on the issue and collapsed last week as a result of tensions over the Georgia war.

The Russian Foreign Minister, Sergei Lavrov, has already served notice that Ukraine faces a 100 per cent increase in gas prices from next January. But the obvious flashpoint for any conflict would be over the Crimean Peninsula, the home of the Russian Black Sea Fleet.

Asked whether Russia would take military action against Ukraine, Mr Fedotov stressed that "actually Russia had no plans to take such action in Georgia". "But this action was precipitated by this stupid military intervention against the peaceful population in Tskhinvali."

He added: "I hope that people would take some lessons from what happened in South Ossetia."

Turning to relations with Britain, he blamed the British Government for the deterioration in ties since the expulsion of Russian diplomats in July 2007 over the poisoning of Alexander Litvinenko. He said Britain`s decision last week to bar military pipers from a Red Square festival was "awkward" but unlikely to cause a further downturn.

The Independent