A liberal party in Serbia demanded the expulsion of the Russian ambassador Sunday after he appeared at a nationalist gathering.
Ambassador Aleksandr Konuzin has been meddling in Serbia's internal politics and should be declared persona non grata, the League of Social Democrats of Vojvodina, or LSV, said in a statement.
Konuzin on Saturday attended an anniversary meeting of the opposition nationalist Serbian Progressive Party. Serbian media quoted Konuzin as saying that the party "has become a true reflection of the popular mood" in Serbia.
The liberals say such statements amount to open support for the nationalists ahead of next year's elections, which will pit the ruling pro-Western reformists against the nationalists.
The LSV party statement said "the ambassador of the Russian Federation in Serbia has definitely shown ... that the Russian Federation has been meddling in Serbia's internal affairs on an unbearable scale."
Serbia's deputy Prime Minister Bozidar Djelic said he was sure that "Russia wouldn't like see the same behavior of foreign ambassadors" on its turf.
There was no immediate reaction from the Russian embassy in Belgrade. No one was available for comment at the Russian Foreign Ministry in Moscow.
Another pro-Western party, the Social Democratic Union, also described Konuzin's comments as "the latest in a series of incidents," and "open abuse of hospitality."
Konuzin has clashed in the past with Serbia's liberals, who have accused him of non-diplomatic behavior.
He recently stormed out of a security forum in Belgrade, accusing its participants of not doing enough to defend Serbia's claim to the breakaway province of Kosovo, which declared independence in 2008.
Russia is Serbia's traditional Orthodox Christian ally and has backed the country in its opposition to Kosovo independence.
Serbia's nationalists have advocated stronger ties with Russia and the abolition of the EU bid because of Western support for Kosovo's statehood.