Presidential candidate and leader of Russia's leading liberal party Grigory Yavlinsky said Monday that election officials' refusal to clear his candidacy for March's presidential election reflects the government's fear of genuine competition. (Alexander Zemlianichenko/AP)

Russian election officials are threatening to bar a veteran liberal politician from running for president, prompting allegations of bias and interference that echo complaints of misconduct in December’s parliamentary elections.

The candidate, Grigory Yavlinsky, accused the ruling United Russia party of trying to disqualify him so that his supporters would not be eligible to be observers in the March 4 elections.

The Central Election Commission said that too many of the signatures on Yavlinsky’s nominating petitions are suspect. Candidates whose parties are not represented in the parliament — and Yavlinsky’s Yabloko party is not — must present 2 million signatures to be registered to run.

“The decision now in the making is purely political, and it has nothing to do with signatures, with the quality or anything else,” Yavlinsky, who stands almost no chance of winning the election, said at a news conference Monday.

Another outsider candidate, the billionaire Mikhail Prokhorov, jumped to Yavlinsky’s defense. He said that barring Yavlinsky would be “dishonest, unfair and destructive.” Yabloko, Yavlinsky’s party, received more than 2 million votes in December, Prokhorov noted, and that in itself should ensure Yavlinsky’s right to run.

Removing Yavlinsky, Prokhorov said, would taint the entire election.

The elections commission came under strong criticism from both Russians and foreign observers for the conduct and alleged falsification of the December parliamentary elections.

Prokhorov himself is in a potentially delicate situation. Critics charge that he is running for president at the behest of the Kremlin, to split the liberal vote and give the election an appearance of legitimacy. He denies that charge. But the election commission, which is firmly under Kremlin control, appears to be giving him an easy ride. An official said Monday that the commission sees no problem with the petitions Prokhorov submitted, and probably will register him as a candidate in the next day or two.

The contrast with the treatment of Yavlinsky, a fixture on the political scene since his days as an adviser to the last Soviet leader, Mikhail S. Gorbachev, looks incriminating. Prokhorov said Monday that the whole situation could be a “provocation.”

He called on all candidates to use whatever political influence they have to ensure Yavlinsky’s presence on the ballot. That presumably includes Prime Minister Vladimir Putin, the front-runner and a man whom the election commission would almost certainly obey, if he gave the word.

Moscow, which has been rocked by a series of mass demonstrations since the December voting, is facing another big protest rally Feb. 4. On Monday a leader of the Democratic Choice party, Vladimir Milov, tweeted that the registration of Yavlinsky as a candidate will be added to the protesters’ demands.

At the same time, Yavlinsky has not yet been formally rejected. An election official told the Interfax news agency that about a quarter of the signatures he submitted were suspicious, but the commission intends to review them again before coming to a decision. The governor of the Irkutsk region, Dmitry Mezentsev, also faces elimination as an independent presidential candidate over the signatures he submitted.