Russia's Vladimir Putin promised he would not crack down on Russia's burgeoning opposition movement following his likely election as president on Sunday, but rejected protesters' calls for early parliamentary polls.

Tens of thousands of people have turned out for protests in Moscow and other cities since a disputed parliamentary vote in December - the biggest protests of Putin's 12-year rule.

The unprecedented wave of demonstrations has cast a shadow over the powerful prime minister who appeared politically invincible throughout much of his rule.

In remarks published on Friday, Putin signaled he was confident he could maintain control and popular support without tightening the screws or giving in to opponents' demands.

Asked in a meeting with foreign newspaper editors whether he would move to crack down on the opposition after the vote, Putin quipped: "Why do I need to do that?"

"I don't know where these fears come from. We are not planning anything of the kind," Putin said at the meeting held on Thursday at his residence outside Moscow.

Russian authorities have often used heavy-handed tactics to deal with dissent but have shown restraint toward the recent protests, holding talks with leaders to agree locations. Police have been out in force but have intervened rarely.

But some activists fear that the picture would change after the Sunday election and a political crackdown would follow. In his remarks, Putin dismissed such fears.

"On the contrary all of our proposals are geared toward establishing a dialogue with everyone, with those who support us and those who criticize us," he said in a transcript posted on the government's website.

He said he and President Dmitry Medvedev were working to liberalize the political system, which he tightened during his 2000-2008 presidency, by reinstating popular elections of regional governors and allowing more political parties.

More firmly than before, however, he ruled out holding a early parliamentary election - one of the main demands voiced by protesters angry over suspected fraud in his ruling party's favor in a December 4 vote and dismayed by his plans to stay in power for a last six more years.

"No," he said when asked whether he would call for an early election.

The opposition hopes to keep up pressure and plans protests in central Moscow and other cities on Monday. Opposition leaders say they suspect the vote will be rigged to ensure he avoids a second-round runoff by winning more than 50 percent.

The protests were fueled by suspicions Putin's United Russia party cheated in the December polls and served as an outlet for anger over Putin's plan to swap jobs with Medvedev.

The plan deepened frustrations among Russians who believe the formal elections give them little real say in politics.

Putin defended his decision, saying he and Medvedev 'honestly and clearly told the country' of their plans ahead of the parliamentary and presidential elections.

"Did we trick anybody? ... No," he said. Putin, who will be inaugurated in May if he wins the presidency, reiterated that he plans to make Medvedev prime minister.

In the latest opinion survey by independent pollster Levada Center, conducted in February, 66 per cent of voters who planned to vote and had decided on a candidate said they would vote for Putin.

Putin, who steered Medvedev into the Kremlin in 2008 and became prime minister when he faced a constitutional bar on a third consecutive term as president, could run for another six -year term in 2018.

He suggested serving another term after 2018 would be 'normal, if everything is working out, if people like it'.

"But I don' know whether I want to sit (in power) for 20-odd years. I have not yet decided for myself."