Labour MP Mike Gapes calls for prince to 'abdicate and stand for election' if he wants to make controversial statements

Prince Charles is facing a call for his abdication and a frosty response in Moscow after reportedly comparing Vladimir Putin to Adolf Hitler over Russia's annexation of Crimea.

Charles blundered into the international crisis over Russia's actions in Ukraine during a tour of Canada, when he spoke to a woman who fled the Nazis and lost family members during the Holocaust.

According to the Daily Mail, the prince compared the Russian president to the Nazi leader when talking to Marienne Ferguson, a museum volunteer who moved to Canada with her Jewish family when she was just 13. "Now Putin is doing just about the same as Hitler," Charles is reported to have said.

Charles's remarks have been criticised across the political spectrum in Britain: the Labour MP Mike Gapes called for his abdication, while the outspoken Ukip leader, Nigel Farage, said the prince was wrong to get involved.

Putin's spokesman, Dmitry Peskov, pointedly refused to discuss the issue when approached by journalists. But the popular Russian daily Moskovskij Komsomolets (MK) said Charles's remarks risked "triggering an international scandal".

MK said Charles's comments risked complicating already "clouded" UK-Russian relations.

Peskov initially said he knew nothing about the comments, according to Sky News. He later told the BBC's Moscow correspondent, Steve Rosenberg, the Kremlin was "not commenting right now" on the story.

Anti-Russia activists in Ukraine praised Charles's remarks. "Good old Charley," commented one contributor to the Facebook page of Euromaidan, which helped organise the protests in the Ukrainian capital Kiev that led to the ousting of the pro-Russia president Viktor Yanukovych.

Labour MP Gapes, a current member and former chairman of the House of Commons foreign affairs committee, said the prince should have kept his views private. The Ilford South MP tweeted: "If Prince Charles wants to make controversial statements on national or international issues, he should abdicate and stand for election.

Ukip's Farage is reported to have said: "There are times when it might be better for Prince Charles not to get involved in things like this."

Britain's former ambassador to Russia, Sir Tony Brenton, said it was a "grotesque exaggeration" to compare Russia's actions in Crimea with those of the Nazis. But he said Charles' intervention could help Russia reconsider its policy in Ukraine.

Speaking to BBC News, Brenton said: "It will be picked up in public circles in Russia .. The Russians have taken over Crimea, they are debating with themselves about where to go next. The fact that they have generated the impression in some minds that they are behaving a bit as Hitler behaved, while I think is a false judgement, will help [them] to reconsider a little bit."

Brenton added: "Hitler is the ultimate ogre in Russian public opinion ... The fact that Russian policy is generating these sort of reactions ought to have a calming effect there."

Brenton who served as ambassador to Moscow between 2004 and 2008 added: "Russia is having quite a nationalist moment, but the judgment that Putin is behaving like Hitler, is very mistaken. The annexation of Crimea was entirely illegal and wrong but to say that that leads us in the direction of a revanchist Russia - the bear being on the prowl again - is a grotesque exaggeration."

Deputy prime minister, Nick Clegg, said Charles was "free to express himself".

Speaking to BBC Breakfast, Clegg said: "I have never been of this view that if you are a member of the royal family somehow you have to enter into some Trappist vow of silence. I think he is entitled to his views. But I don't know whether those were his views because I just don't think providing a running commentary on what were private conversations is useful to anybody.

"I don't know exactly what he did or didn't say in that conversation because he thought it was a private conversation," Clegg added.

Asked if he agreed there were parallels to be drawn, he said: "I'm not going to start comparing one period of European history to another.

"People can make different comparisons from different periods of history if they wish. All I would say is that right now I think the behaviour of Putin is not only menacing to Ukraine but it is very destabilising for Europe more generally.

"That is why we continue to say to the Russians, continue to say to Vladimir Putin: step back, de-escalate. It's not in Russia's interests, let alone anybody else's, to continue ratcheting up this tension."

The Conservative party chairman, Grant Shapps, told BBC Radio Berkshire that it was not the convention for politicians to comment on remarks made by the royal family. "There's a long-held convention that royals have the opportunity to comment and they do. Usually politicians don't comment on what the royals are saying. People can hear what someone has said; it stands on its own."

He added: "It is not for ministers to comment on what our royals say. They can perfectly well express their opinions, as Prince Charles has done in this case. One of the important lesson from the second world war is to make sure that there is a proper response to what happens."

A spokesperson for Clarence House said: "We would not comment on private conversations. It was a private conversation at a reception for war veterans."

The Daily Mail reported that Ferguson said: "'I had finished showing him the exhibit and talked with him about my own family background and how I came to Canada. The prince then said 'And now Putin is doing just about the same as Hitler'."

"I must say that I agree with him and am sure a lot of people do. I was very surprised that he made the comment as I know they [members of the royal family] aren't meant to say these things but it was very heartfelt and honest."

The comments came just over a fortnight before Charles is due to meet Putin at the commemorations of the 70th anniversary of the D-Day landings in Normandy on 6 June. He and the duchess are currently on a four-day tour of Canada.

A recent visit to Estonia by the prince's youngest son, Harry, was viewed by many commentators as a sign of western support amid fears of a resurgent Russia; the region has seen a rise in tensions since the crisis in Ukraine. Harry also met with Estonian, British and US service personnel involved a major Nato training exercise.