The seemingly off-the-cuff comment reportedly made by Prince Charles in Halifax comparing Russian President Vladimir Putin's actions in Ukraine to the territory-seizing of Adolf Hitler has stirred debate in the United Kingdom about the role of the monarchy.
Labour party MP Mike Gapes weighed in with a tweet that suggested the Prince of Wales should have kept his comments to himself.
"In constitutional monarchy policy and diplomacy should be conducted by parliament and government. Monarchy should be seen and not heard," he tweeted.
When someone asked him about the prince's right to free speech, he replied on Twitter: "If you are heir to throne or monarch what you say matters. Normal 'free speech' argument not relevant."
But Deputy Prime Minister Nick Clegg told the BBC the prince was "free to express himself."
"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," said Clegg. "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."
Britain's Daily Mail said Charles made the comment during a visit Monday to the Canadian Museum of Immigration in Halifax.
The newspaper reported museum volunteer Marienne Ferguson as saying her Jewish family fled to Canada from Poland when she was 13, but that other relatives failed to flee before the German army arrived in Gdansk in 1939.
It quoted Ferguson as saying she told Charles about her family background and how she came to Canada, and that Charles then said to her: "And now Putin is doing just about the same as Hitler."
The Canadian Press could not reach Ferguson for comment about the report.
A spokeswoman for Clarence House, the residence of Prince Charles, told the news agency early Wednesday, ‘‘We don‘t comment on private conversations.‘‘
‘‘We do like to stress that the Prince of Wales wouldn’t seek to make a political statement during a private conversation,‘‘ the spokeswoman added.
Ferguson later told the BBC it was "just a little remark. I didn't think it was going to make such a big uproar."
Tensions have grown between Putin and the West since Russia's annexation of Crimea earlier this year.
Charles has sometimes been accused of compromising the Royal Family's political neutrality with his strong views on topics including education, architecture and the environment.
He is due to join the Queen and leaders of the Second World War Allies — including Putin — at events in France on June 6 to mark the 70th anniversary of the D-Day landings that led to the liberation of Europe. There was no immediate comment reported from Russian officials.
The prince and his wife, Camilla, are scheduled to wrap up their trip to Canada today in Winnipeg.