Russia has vowed to respond to Britain's decision to expel four diplomats in a dispute over the case of a former KGB agent fatally poisoned in London, and warned the move could badly damage ties between the nations.
"They should understand well in London that the provocative actions conceived by the British authorities will not go unanswered and cannot fail to produce the most serious consequences for Russian-British relations as a whole," Foreign Ministry spokesman Mikhail Kamynin said Monday.
He said Foreign Minister Sergey Lavrov had relayed the same message to British Foreign Secretary David Miliband in a telephone call.
Kamynin spoke at a hastily arranged briefing after Miliband announced the decision to expel four Russian diplomats and place restrictions on visas issued to Russian government officials over Moscow's refusal to extradite Andrei Lugovoi, the key suspect in the killing of Alexander Litvinenko last year.
Kamynin called Britain's decision "a well-staged action to politicize the Litvinenko case."
He claimed that the British government was trying to justify its own refusal to extradite two prominent Kremlin foes who have asylum in Britain, tycoon Boris Berezovsky - an associate of Litvinenko - and Chechen separatist figure Akhmed Zakayev.
"One gets the impression that with such actions the British authorities are trying to justify, in the eyes of the world public, their refusal to work with Russian law enforcement bodies on the question of the extradition to Russia of Berezovsky and Zakayev, in relation to whom we have given irrefutable evidence of involvement in terrorist activity," he said.
"Against this background, the position of Britain is immoral," he said.
Lugovoi said the British moves "show that the results of this investigation were predictable from the very beginning and have always had a political character."
Speaking on state-run Channel One television, he said "all (British) announcements that the investigation was conducted competently are lies."
Kamynin did not say how Russia would respond.
"We will resolve these issues in a constructive way, without politicizing them," he said.
Kremlin-connected political analyst Vyacheslav Nikonov said he expected Russia would respond with identical measures, as in past disputes between Moscow and London going back to the Soviet era.
"The usual practice is an absolutely symmetrical response that would not lead to an escalation of the conflict," said Nikonov, one of several prominent Russian analysts and lawmakers who sneered at the Miliband's announcement on state-run Vesti-24 television, which broadcast it live.
"It's clear that Russia's response can only be the same, only symmetrical, only a mirror image - and of course, swift," said Konstantin Kosachyov, head of the international affairs committee in the State Duma, the lower parliament house.
"We must show the whole world in this situation that we can flawlessly defend our positions and our interests in a legal way," he said. He accused Britain of trying "to force an inferiority complex on Russia," but said Russia has "grown out of our short pants" and knows how to conduct itself.
Duma lawmaker Andrei Kokoshin said that Moscow could take other unspecified measures and warned that "Britain will suffer a far greater loss in this situation" than Russia.
Kokoshin suggested that a resurgent, energy-rich Russia holds the upper hand in economic ties and would be hurt less than Britain if the bilateral business climate is damaged.
A British Embassy spokesman, speaking on customary condition of anonymity, said that "any Russian retaliation against these measures would be wholly unjustified."
"Given the importance of this issue, and Russia's failure to cooperate to find a solution, we needed to give a firm diplomatic response," he said.
The British press has recently reported that Russia was going to conduct a nuclear test either on the borders with Ukraine or in the Black Sea.