The youthful, Internet-savvy Russians who have turned out in the streets in historic numbers in recent weeks want to end Prime Minister Vladimir Putin’s untrammeled rule over their country, but whether they can translate their frustration to the political arena — or even whether they will remain fired up — remains an open question.

Much of the country’s young post-Soviet middle class stayed apolitical until recent months, and the established opposition parties have been slow to capitalize on the discontent. On Monday, the planners of a Christmas Eve protest agreed to focus on denying Putin the presidency in March. But they did not discuss a candidate for whom they would campaign, in part because few new faces are on the scene.

The latest disappointment for the young organizers came Monday when the reformist Yabloko party filed papers to nominate its longtime leader, Grigory Yavlinsky, 59, for president, rather than a charismatic blogger, Alexei Navalny, 35, who has been a galvanizing force behind the protests. Many of the young generation thought that nominating Navalny was the fastest path to a re-energized electorate, although some have questioned his strident nationalism.

The party rejected consideration of the blogger at a weekend meeting, saying he had not submitted a written application. But filling out the form would have been difficult: Navalny has been in prison, accused of obstructing traffic during an unsanctioned protest, since the day after the Dec. 4 parliamentary elections.

That there is serious discussion about challengers to Putin is itself a major departure for a country where just weeks ago any chinks in his armor appeared theoretical at best.

“There is a demand for changes in society, and such changes are not possible without new faces in politics,” said Nikolai Kuznetsov, a member of Yabloko who had pushed for the blogger to be the party’s nominee. “Navalny’s supporters are active young people. They are the ones who are building civil society in Russia. Because of him, people in Russia now understand that the United Russia party is a party of crooks and thieves,” he said, referring to a phrase Navalny coined that has become a popular way to refer to Putin’s party.

It remains unclear whether Yavlinsky will make it onto the ballot. He and billionaire New Jersey Nets owner Mikhail Prokhorov, 46, who declared his intention to run last week, will each have to collect 2 million signatures by Jan. 18 to qualify — working through the New Year’s and Christmas holidays, when much of the country goes on vacation. According to the disputed official results from the Dec. 4 elections, Yavlinsky’s party received 2.3 million votes nationwide.

Prokhorov, a pro-business candidate who has espoused democratic reforms, could attract liberal support, but some analysts here have questioned whether he has been put up by the Kremlin to split the reformists’ vote.

If neither Prokhorov nor Yavlinsky makes it onto the ballot, Russians most likely will choose among an ultra-nationalist, a Communist nostalgic, a candidate who until this year was close to Putin, and Putin himself — unappetizing options for the protesters, many of whom were uninterested in politics until very recently, content to prosper as the run-up in oil prices drove government spending during Putin’s first decade in power.

Withered by the Putin years, few political parties cater to a youthful audience.

Yabloko would once have been the most natural fit for many of the protesters, analysts say. But “most of the members are pensioners, or close to retirement age,” said Kuznetsov, 30, who said he was one of the party’s youngest officials.

Civic organizations have sprung up in recent years — one dedicated to saving a forest on the outskirts of Moscow from development, another devoted to fighting the blue lights that the rich and powerful put on top of their cars so they can speed around Moscow’s always-snarled traffic — but their broader political aims remain muted, and when their leaders have turned toward the established parties, they have been rebuffed.

The existing politicians “cannot meet our demands,” said Yevgenia Chirikova, who has led the residents’ movement against development in Khimki Forest, a 2,500-acre stand of centuries-old oaks and birches that is in the way of a planned highway from Moscow to St. Petersburg. She spoke Sunday at the Yabloko convention in favor of making Navalny the party’s presidential nominee. In her years-long fight to save the forest, which now appears doomed, “we did everything ourselves without any political parties” to help — not because the campaigners wanted to, but because the parties weren’t in a position to make a difference, she said.

“What’s happening in Russia right now is that people are organizing themselves,” without professional politicians, she said.

Some here argue that a new era awaits Putin even if he wins the March presidential election and that the years of his unquestioned rule are over.

“My hunch is that we are at the beginning of the first act,” said Lilia Shevtsova, an analyst at the Carnegie Endowment for International Peace in Moscow. “But developments are moving unbelievably fast.”