The Queen has been canvassing opinion on the EU debate by asking dinner companions: "Give me three good reasons why Britain should be part of Europe."

Her Majesty's biographer, Robert Lacey, reported the Queen's comments and suggested they may mean the Queen favours withdrawal from the European Union.

Buckingham Palace would neither confirm nor deny that the Queen had been debating the merits of Brexit in private, but royal sources pointed out that the words attributed to the Queen were "a question not a statement".

However the leading nature of the alleged question adds weight to previous claims that the Queen would like Britain to pull out of the EU.

Last month the press regulator found that the Sun newspaper had been guilty of "significantly misleading" its readers when it printed the headline "Queen backs Brexit" above a story about the Queen complaining about Brussels to Nick Clegg.