The Queen has been reported as backing Britain's exit from the European Union following comments she is said to have once made to the former Liberal Democrat leader Nick Clegg as well as in a separate conversation with MPs.
During the last government at a lunch at Windsor Castle attended by other ministers, she allegedly told Clegg that she believed the EU was heading in the wrong direction.
A source told The Sun: "People who heard their conversation were left in no doubt at all about the Queen's views on European integration. It was really something, and it went on for quite a while. The EU is clearly something Her Majesty feels passionately about."
Separately, at a Buckingham Palace reception, the Queen was asked by MPs in a circle with her what her opinion on Brussels was, to which she reportedly replied: "I don't understand Europe".
A parliamentary source, which The Sun described as "impeccably placed" said: "It was said with quite some venom and emotion, I shall never forget it."
The Monarch stands above politics although she was seen to have made her feelings known during the referendum on Scottish independence in 2014 . Then she told people after a church service that voters should "think very carefully" before making a decision.
Buckingham Palace has not yet formally denied the anti-EU remarks, insisting that the Queen is "politically neutral" and would not comment on the claims.
Nick Clegg said he did not recall the details of what was said in the conversation with the Monarch.
He said: "I don't have a photographic memory. But I think I would have remembered something as stark or significant as you have made it out to be."
He added: "Anyway, without sounding pompous, I find it rather distasteful to reveal conversations with the Queen."
On Tuesday 8 March, governor of the Bank of England Mark Carney said that Britain leaving the EU would be the "biggest domestic risk to financial stability" although he said that the Bank would not take sides in the referendum.