The Organisation for Security and Co-operation in Europe (OSCE) on Thursday canceled its observer missions for Russia's March 2 presidential election because of restrictions imposed by Moscow.
The OSCE election watchdog and its parliamentary assembly both said they would boycott the vote, which President Vladimir Putin's designated successor Dmitry Medvedev is virtually guaranteed to win.
Russia's opposition already alleges Putin is rigging the vote and the absence of Europe's main election monitoring body will cast further doubt on the legitimacy of the democratic process in Russia.
The OSCE presidency, currently held by Finland, regretted the decision, "despite constructive efforts on both sides." The chief of the body's monitoring division blamed "limitations imposed by Russia."
While Russia had invited the OSCE to come to Moscow, numerous restrictions rendered the invitation worthless, said Christian Strohal, head of the Office for Democratic Institutions and Human Rights, the OSCE polls division.
"We've been bending over backwards in order to find a way which would allow at least a limited observation activity," he said. "This was not possible, not because of us but because of restrictions and limitations imposed by Russia."
It was like being invited "to come through a door which is locked."
Russia, like all the OSCE's 56 members, is meant to invite monitors to assess whether elections are free and fair.
The boycott is a snub to Putin's government, already embroiled in a slew of conflicts with EU member states ranging from Kosovo's independence drive to NATO expansion and spying allegations.
The Russian foreign ministry called the boycott "unacceptable" and Foreign Minister Sergei Lavrov said it was an "ultimatum."
"Self-respecting countries do not accept ultimatums," he said.
The EU presidency blamed the boycott on "restrictions contained in the invitation."
European External Affairs Commissioner Benita Ferrero-Waldner urged the Russian authorities "to make sure that these elections will be conducted in accordance with Russia's commitments as a member of the OSCE."
The White House gently reminded Moscow that the presence of the observers was not a black mark against Russia.
"It shouldn't be seen as a stigma ... We think Russia and all countries should feel open enough to allow observers into their country to keep an eye on elections," a spokesman told reporters.
Russia is frequently critical of the organization, accusing it of bias against countries of the former Soviet Union and calling for a major reform of the body.