Russia has demanded talks with the Foreign Office following Prince Charles comments comparing Vladimir Putin to Hitler.
UK diplomats will seek to head off any diplomatic row in a meeting with the Russian deputy ambassador Alexander Kramarenko ahead of a meeting between the Duke of Cornwall and the Russian President next month.
The Prince made his comments in a private conversation with a Jewish museum volunteer whose family fled Nazi Germany during the war during a Royal tour of Canada.
He had been visiting the Museum of Immigration in Halifax, Nova Scotia, with his wife, the Duchess of Cornwall, to pay tribute to Second World War veterans.
Marienne Ferguson, 78, said that after telling the Prince the story of how her family fled the Nazis he replied: “Putin is doing just about the same as Hitler.”
Russia has now called for a meeting to clarify whether the Prince’s comments were an “official position”.
“The response from Clarence House is it was a private talk. We hope there is nothing behind it. But it is unclear to us: what does it mean? He is the future king, after all,” a senior Russian diplomatic source told The Daily Telegraph.
The diplomat said the comments had sparked significant consternation because of the scale of Russian casualties in the Second World War and added: “It is very serious. Every family in our country lost someone in that war.”
The Prince is due to meet Mr Putin at commemorations for the 70th anniversary of the D-Day landings in Normandy on June 6.
Prime Minister David Cameron on Wednesday refused to comment on the Prince’s remarks, which were reported in the Daily Mail, but said: “Everyone is entitled to their private opinions.”
Labour leader Ed Miliband said the Prince “has got a point” about the Russian President’s actions in Ukraine and said many may share his view.
Deputy Prime Minister Nick Clegg said the Prince should be entitled to express his privately held views, while Nigel Farage rejected the Prince’s Hitler comparison.
A spokesman for Clarence House said: “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.”
Mrs Ferguson had told the Daily Mail: “The Prince 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. But 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.”
22 May 2014 | 12:31 pm – Source: orange.co.uk