The Russian opposition figure and former world chess champion, Garry Kasparov, will no longer contest the presidential election next March.
Mr Kasparov is among the Kremlin's fiercest critics
Mr Kasparov said his Other Russia bloc had faced difficulty arranging for its supporters to meet in Moscow - an official requirement for his candidacy.
The former chess player has frequently accused President Vladimir Putin's government of throttling opposition.
A Putin aide, Dmitry Medvedev, is expected to succeed him as president.
Earlier this week, Mr Putin named Mr Medvedev, currently the first deputy PM and chairman of gas giant Gazprom, as his choice for president.
Mr Putin's own popularity is likely to ensure his nominee gets the job, analysts say.
Though constitutionally obliged to step down in March, Mr Putin is expected to retain political influence - possibly by becoming prime minister.
Parliamentary elections in Russia earlier this month delivered a landslide victory to United Russia, the largest party in the Duma loyal to the Kremlin.
Other Russia - a coalition of mainstream politicians, as well leftists and nationalists opposed to the Kremlin - did not meet legal requirements to field candidates.
Mr Kasparov announced on Wednesday that he was abandoning his campaign for the presidency.
Other Russia activists clashed with riot police at a recent rally
"My electoral campaign finishes tomorrow," Mr Kasparov said, citing problems in finding a place to hold a meeting of his supporters in Moscow.
Under Russian election law, presidential contenders who are not affiliated to one of four major parties that won seats in parliament must provide the details of two million supporters across the country.
Such contenders must also organise an "initiative group" meeting of at least 500 supporters before a December deadline.
"In all Moscow we have not been able to find a hall where our supporters could meet," Mr Kasparov said.
"We pay and the people agree. There are no problems. And then they call us to say they are refusing, can't give us the hall any more," he said.
"They refuse to give us the hall for technical reasons."
Mr Kasparov has accused Mr Putin of stifling the opposition through its dominance of the media and through new electoral laws that allegedly favour pro-Kremlin parties.
The former chess star, who represented the Soviet Union at tournaments in the 1980s, was arrested and jailed for five days before the recent election for taking part in an illegal rally.