LONDON (AFP) — British politicians defended the right of Prince Charles to speak his mind on Wednesday after he reportedly compared the actions of Russian President Vladimir Putin in Ukraine to those of Adolf Hitler.

The heir to the throne made the apparently unguarded comment during a trip to a museum in Canada, in private conversation with a Polish-born woman who had fled the Nazis as a child.

“I had finished showing him the exhibit and talked with him about my own family background and how I came to Canada,” 78-year-old Marienne Ferguson told the Daily Mail newspaper.

“The prince then said: ‘And now Putin is doing just about the same as Hitler.'”

The remark made headlines around the world, and Russian media said it threatened to further “complicate” relations between Britain and Moscow.

Charles and Putin are both attending commemorations marking the 70th anniversary of D-Day on June 6, although royal aides said no formal meeting was scheduled.

UK Prime Minister David Cameron declined to comment on a private conversation, but said: “Of course, everyone is entitled to their private opinions.”

Deputy Prime Minister Nick Clegg said the future king was “free to express himself.”

Opposition Labour leader Ed Miliband went even further, saying: “I think he has got a point about President Putin’s actions, and I think he is absolutely entitled to say that there are real concerns about that.”

However, Labour lawmaker Mike Gapes, a member of the House of Commons foreign affairs committee, said the royals “should be seen and not heard.”

“If Prince Charles wants to make controversial statements on national or international issues, he should abdicate and stand for election,” he said on Twitter.

The prince’s office would not confirm the remarks but said he would not have intended to make a political statement.

“We do not comment on private conversations. But we would like to stress that the Prince of Wales would not seek to make a public political statement during a private conversation,” a spokeswoman said.

‘Just a little remark’

The prince reportedly made the remark during a tour of the Canadian Museum of Immigration in Halifax, Nova Scotia, as part of a four-day trip to Canada with his wife Camilla.

Ferguson, who moved to Canada with her Jewish family when she was 13 and who lost relatives in the Holocaust, confirmed her account of their conversation in a later interview with the BBC.

She added that it was “just a little remark — I didn’t think it was going to make such a big uproar.”

Members of the royal family by convention do not comment on political affairs, and Queen Elizabeth II is famous for keeping her own counsel.

However, her 65-year-old son Charles has come under criticism in the past for his outspoken remarks about everything from genetically modified food to architecture.

There was no official reaction in Moscow to his comments, but the popular daily Moskovsky Komsomolets said the timing was “badly chosen” ahead of the D-Day commemorations.

On its website, it also said the remarks “risk triggering an international scandal and complicate the already clouded relations between Great Britain and Russia.”

Ties between London and Moscow were plunged into deep freeze following the 2006 murder of Alexander Litvinenko, a Russian dissident, in London.

Relations began to improve in 2011, but the crisis over Ukraine has led to fresh tensions as the United States and the EU imposed sanctions on Russia for its intervention in the former Soviet state.

A spokeswoman for Britain’s Foreign Office told AFP that “it is not for us to comment” on the prince’s remarks.

Former US secretary of state Hillary Clinton made a similar comparison at a private event in March, according to a local newspaper report.

Describing how Moscow justified sending more troops into Crimea as a way to protect Russian speakers from a pro-Western government, Clinton said: “If this sounds familiar, it’s what Hitler did back in the 30s.”

The Russian foreign ministry last month complained to the German ambassador after Finance Minister Wolfgang Schaeuble reportedly drew parallels between Moscow’s annexation of Crimea and Hitler’s aggression in Czechoslovakia on the eve of World War II.