'Unfriendly actions'
 
He said: "We are disappointed that the Russian government should have signalled no new co-operation in the case of the extradition of Mr Andrei Lugovoi for the alleged murder of Alexander Litvinenko."
 
Mikhail Kamynin, a Russian foreign ministry spokesman, earlier said the British ambassador had been summoned and handed a note "in connection with the unfriendly actions of Britain towards Russia".
 
"Four British embassy staff in Moscow are now persona non grata and they should leave the territory of the Russian Federation within 10 days," he said.

The Russian foreign ministry spokesman said the measures announced by London earlier in the week were "unfriendly and provocative" and called for "common sense" to prevail in the row, saying: "Moscow did not pick this fight."
 
Moscow said its constitution bans extradition and Vladimir Putin, the Russian president, has called the request "stupid".
 
'Terrible crime'
 
Lugovoi has appeared numerous times in front of the media in Russia insisting he is innocent and accusing British intelligence of being involved in the murder of Litvinenko.
 
The European Union and the United States have supported Britain against Russia in the row, which comes amid a wider deterioration of relations between the West and Russia as a result of Putin's more assertive foreign policy.

Condoleeza Rice, the US secretary of state, said: "A terrible crime was committed on British soil and Britain has to find the perpetrators and bring them to justice and Russia should honour the extradition request."
 
Litvinenko, a former Russian security officer who had been critical of his former bosses, died in a London hospital in November after apparently being poisoned with radioactive polonium-210.