The Sun argues Queen 'statistically likely' to back Brexit amid calls for inquiry into contested report

Buckingham Palace has launched an official complaint and Nick Clegg called the story 'nonsense'

Copies of Britain's 'The Sun' newspapers are sold at a store in London, Britain, 09 March 2016. (EPA)

The Sun has claimed the Queen is “statistically more likely” to back a Brexit because of her age and education level while defending its controversial report.

A front page story claiming the monarch had voiced strong Eurosceptic views during a lunch at Windsor Castle in 2011 has sparked calls for an investigation and a formal complaint to a media watchdog.

It claimed that two “impeccably placed” sources recounted how she had vented her anger with Brussels at Nick Clegg, who is pro-EU, his time as Deputy Prime Minister.

Buckingham Palace lodged a formal complaint with the Independent Press Standards Organisation on Wednesday and Mr Clegg called the article “nonsense” but the Sun has stood by its report.

Tony Gallagher, the paper's editor, said he had no doubt it was accurate and claimed journalists knew “much more” than was published.

“Multiple sources - two sources to be precise - came to us with information about the Queen and her views on the EU and we would have been derelict in our duty if we didn't put them in the paper. It's as simple as that,” he told the BBC Radio 4 Today programme.

“You are going to have to take my word for it that we are completely confident that the Queen's views were expressed exactly as we have outlined them both in the headline and the story.”

In its coverage today, the newspaper accused Mr Clegg of attempting to “gag” Brexit campaigners and accused pro-EU figures of attempting to discredit the report because of the effect it could have on undecided voters ahead of the June referendum.

A report claimed that YouGov polls showed that “statistically the Queen is in a group highly likely to back Brexit”, adding: “Women aged over 60 without a university education back leaving the EU by 73 per cent.”

Michael Gove blamed the EU for the worst upsurge in the far right at “any time since the 1930s” (Getty Images)

The Cabinet Secretary, Sir Jeremy Heywood, is facing calls to investigate who leaked the information - with Michael Gove seen as the prime suspect.

The Justice Secretary - who is an ardent Leave supporter - was one of four ministers, including Mr Clegg, to attend the only lunchtime meeting of the Privy Council to be held at the castle during 2011.

The then Welsh secretary Cheryl Gillan, who also backs Brexit, was also present. Neither has commented on the report.

Wes Streeting, the Labour MP for Ilford North, wrote to Sir Jeremy urging him to investigate the leak, saying it would be an ”extremely serious breach“ of Privy Council rules if it came from their meeting.

"If it is found that none of those who were present at the meeting in questions are implicated, I urge you to establish which “impeccably placed” individuals were involved in making such allegations to a national newspaper,” he wrote.

Leader of the Commons Chris Grayling, who supports a Brexit, confirmed that conversations with the Queen should always be treated as private but rejected calls for an inquiry.

"We have no idea where this story came from, whether the story is accurate - I have no ability to judge one way or the other,” he said.

"All I know is that it is going to be investigated by the press complaints body and that seems to me the right organisation to look at it.“

Buckingham Palace said its complaint was based on clause one of the Editors' Code of Practice, which governs accuracy.

If Ipso finds against the newspaper, it will have to publish a suitably prominent correction, possibly on its front page, and face a possible fine.

A previous statement on behalf of the Queen said she was “politically neutral” and had remained so throughout her reign, dismissing the “spurious, anonymously sourced claims”.

Additional reporting by PA