Tens of thousands of Vladimir Putin supporters marched through Moscow on Thursday ahead of a gigantic rally seeking to prove his bid for the Kremlin enjoys popular support despite an outburst of protests.

People take part in a procession along Frunzenskaya quay to support presidential candidate and current Russian Prime Minister Vladimir Putin on the Defender of the Fatherland Day near the Moskva River in Moscow February 23, 2012. Russia will go to the polls for a presidential election on March 4. The banner reads, "Russia". REUTERS/Denis Sinyakov

The culmination of the event is set to be a rally in the Luzhniki stadium, a venue with a seating capacity of 80,000 used for Moscow's biggest football matches and rock concerts by the likes of U2.

An AFP correspondent inside the stadium said both the grounds and the stands of Luzhniki were already full. Putin's spokesman Dmitry Peskov, speaking to AFP, refused to confirm or deny if the Russian premier would take part in the rally.

Along the route of the march, the participants were offered free tea and Russian pies dished out from tents erected on the road. Police closed off access to the embankment as soon as it got underway, an AFP correspondent reported.

"We will write our history!" and "Vote for Putin!" were among the slogans brandished by the demonstrators.

The event coincides with Russia's annual Defenders of the Fatherland public holiday, a militaristic celebration that in Soviet times commemorated the achievements of the Red Army and chimes with Putin's rhetoric about Russian might.

In a show of confidence, Putin has until now carried out almost no explicit campaigning, letting his allies represent him in television debates and not entering into the mudslinging between other candidates.

The meeting is organised by Putin's All Russian Popular Front (ONF), a new umbrella grouping of individuals, unions and businesses that emerged for the first time last year to mobilise support for his Kremlin bid.

Russian opposition media have alleged employees at public companies and students have been encouraged or even compelled to take part to swell numbers, while workers have been brought in by train or bus from across Russia.

But Putin's campaign chief Stanislav Govorukhin denied that anyone was being forced to take part in the event, which organisers hope will see 100,000 attend the rally later in the day.

"We are not rounding up anyone, we are inviting everyone," the Interfax news agency quoted him as saying.

The event clearly aims to be a riposte to the three mass rallies staged by the opposition since December 4 parliamentary elections which were tarnished by allegations of widespread vote-rigging.

The opposition says that Putin's once impregnable popularity is plummeting, although his team insist the Russian strongman still enjoys the majority's support.

The pattern of competing protests trying to outdo each other is set to be repeated in the aftermath of the election, with both the opposition and pro-Kremlin youth group Nashi (Ours) vowing mass actions.

Despite the protests, Putin is still widely expected to easily win the election, with the main intrigue focused on whether he will be able to win over 50 percent on March 4 and avoid a second round.

According to a projection by the state-run VTsIOM pollster based on its most recent poll, Putin should win 58.6 percent of the vote, well ahead of his nearest challenger, the Communist Gennady Zyuganov, and three other candidates.

Putin announced in September he would be seeking a third term as Russian president after his four-year stint as prime minister, in a scheme cooked up with President Dmitry Medvedev who should in turn become government chief.