Russia's Foreign Ministry appears set to retaliate after Britain's decision to expel four diplomats amid a deepening row that is pushing relations between the two countries to a new post-Cold War low. The expulsions follow Moscow's refusal to hand
over a suspect in the murder of ex-KGB agent Alexander Litvinenko. A Russian Foreign Ministry spokesman described the UK actions as "immoral". They would not go unanswered, he said, adding they would have "the most serious consequences for Russian-British relations as a whole."

British Prime Minister Gordon Brown struck a similarly hardline note, although he said he wanted a constructive relationship with Russia:

"I have no apologies for the action we have taken, but I do want a resolution to this problem as soon as possible," he said.

British prosecutors want to charge former Russian state security agent Andrei Lugovoi with Litvinenko's murder by poisoning. He says he innocent and Russia says its constitution does not allow extraditions of Russian citizens..

The two countries are already at odds over several issues, including Britain's decision to give asylum to tycoon Boris Berezovsky, an associate of Litvinvenko, and Chechen leader Akhmed Zakayev.

Analysts are divided over whether Moscow will go so far as to respond to the expulsions of its London staff in a similar move.

PHOTO CAPTION

Alexander Litvinenko, former KGB spy and author of the book 'Blowing Up Russia: Terror From Within', is seen photographed at his home in London in this Friday, May 10, 2002 file photo. (AP)