Europe's main election watchdog has said it will boycott Russia's presidential election on 2 March because of Moscow-imposed restrictions.
Questions have been raised about election standards in Putin's Russia
"Russia has made it impossible," said Christian Strohal, monitoring chief for the Organisation for Security and Co-operation in Europe (OSCE).
The OSCE has been arguing with Russia over the size and scope of the observers' mission.
Russia's foreign ministry called the monitors' decision "unacceptable".
"This position can only cause us to feel the deepest regret," spokesman Mikhail Kamynin said.
The watchdog rejected concessions by Moscow aimed at averting a boycott.
Russia had refused permission for his body to send an assessment mission last year, said Mr Strohal, director of OSCE's monitoring wing, the Office for Democratic Institutions and Human Rights (ODIHR).
Moscow had then limited the number of observers and the length of time they could stay in Russia, he added.
"They have imposed restrictions and limitations which do not allow us to deliver a professional job in accordance with our mandate," said Mr Strohal.
The European Union's Slovene presidency said it regretted that due to Russia's restrictions the OSCE's election monitoring wing "was put in a situation where it found it impossible to execute its mandate and cancelled the election observation mission".
It also expressed "its full support to the election observation activities" of the Office for Democratic Institutions and Human Rights (ODIHR).
The OSCE's parliamentary assembly announced its decision in a letter sent to the Russian parliament.
"We unfortunately cannot accept your invitation to send a limited number of observers to Russia for the presidential election," assembly President Goran Lennmarker said in the letter.
Mr Lennmarker also mentioned "other conditions and circumstances", without specifying.
Earlier, Russian Foreign Minister Sergei Lavrov said that no self-respecting country would bow to "ultimatums" of the kind set by the OSCE.
Mr Lavrov urged the ODIHR to stop "inventing instructions"
Mr Lavrov also called for the OSCE election monitoring wing to be reformed, accusing it of working on the basis of rules it invented itself.
The ODIHR and Russia's election commission have been involved in a row over the size and time schedule of the observers' mission.
The ODIHR on Wednesday rejected a commission offer designed to avert a boycott. Russia said it would allow ODIHR observers to arrive on 20 February - a week earlier than Moscow had originally wanted.
The commission also accepted an increase in the number of monitors, from 70 to 75.
But the ODIHR said the offer did not go far enough, insisting on 15 February as the start date.
The monitors had argued that arriving just three days before the vote would mean they could not monitor the election campaign to see if it was free and fair for all candidates, including their access to Russia's media.
Monitors normally arrive in countries up to two months before voting takes place so they can observe the registration of candidates, campaigning and media coverage as well as the vote itself.
The OSCE monitors decided not to observe the parliamentary election in Russia last December because of similar restrictions, the BBC's Richard Galpin in Moscow says.
Western observers who did come to Russia in December criticised the election, saying it had not been fair, our correspondent says.