A host of celebrity musicians and actors have lined up to endorse Vladimir Putin's election campaign, raising questions over their motives and rumours of pressure on stars to back the Russian strongman.

Putin's campaign team has broadcast advertisements on television featuring a roll call of Russian celebrities, each given a minute-long slot to explain "Why I am voting for Putin" in the March 4 presidential election.

While the luminaries chosen include a number of people who have regularly affirmed their admiration for the premier, the surprise appearance of popular actors known for liberally inclined views has ignited a storm of controversy. Allegations have swirled on the internet that some may have been effectively forced to appear for fear of losing official help for charities and cultural institutions in which they are involved.

Actress Chulpan Khamatova, who has built her own children's charity and is something of a heroine for the liberal intelligentsia, said in her pro-Putin video she would be voting for him because he had always fulfilled promises. ...

Journalist Sergei Parkhomenko, one of the leaders of the protest movement against Putin's rule, wrote on his Facebook page: "Dear, deeply-respected Chulpan, we know what they used to blackmail you – the fate of your charity." Russian banking and press tycoon Aleksandr Lebedev, who part-owns the opposition Novaya Gazeta newspaper, wrote on Twitter: "Chulpan! We understand, respect and love (you). And we know everything."

Contacted by AFP, the charity declined to comment. Khamatova neither confirmed or denied the allegations. "Let people say what they want. Leave every person with their view. I'm not going to comment," she told Russian News Service radio. Putin's spokesman Dmitry Peskov denied that any pressure had been put on Khamatova and said she reiterated her support at a visit to a children's hospital with Putin on Wednesday, RIA Novosti said.

The role of artists in politics has particular resonance in Russia, where cultural greats like the playwright Maxim Gorky and the composer Dmitry Shostakovich produced works praising the Soviet authorities while in fear of their personal security.

Another top Russian actor Yevgeny Mironov, who previously had not backed Putin's politics in public, also appeared in a video saying that "Putin is responsible for the country and feels this responsibility like no one else."

Veteran actress Alisa Freindlich, whose career goes back to Soviet classics like Andrei Tarkovsky's Stalker, said in her endorsement she would vote for Putin because she wanted "no more revolutions".

Other endorsements have come from cultural figures who have previously made no secret of their support for Putin including the celebrated conductor Valery Gergiev and the violist Yuri Bashmet.

The controversy has erupted just weeks ahead of the presidential poll where Putin is seeking a historic third Kremlin term in the face of opposition protests fronted by a variety of charismatic figures. Newspaper Vedomosti said that Putin's campaign team was clearly trying with the television spots to counter high-profile opposition activists like the anti-corruption crusader Aleksei Navalny and author Boris Akunin. "Putin's PR people have clearly understood this difference from previous campaigns and thus they started the video campaign," it wrote.