The Queen will attend cabinet on Tuesday to mark her Diamond Jubilee, the first monarch to do so since Queen Victoria.
Downing Street confirmed on Monday morning that the Queen would take a seat alongside David Cameron and his cabinet in No. 10 as an "observer".
The prime minister should have no trouble welcoming the Queen to his house as he is a fifth cousin of the monarch - Christmas is a time for family after all.
Cameron is said to have got a helping hand for Her Majesty when he applied for his first job at Conservative Central Office in the late 1980s.
According to a biography the man due to interview the young Cameron received a phone call from the Palace telling him: "I am ringing to tell you that you are about to meet a truly remarkable young man."
Last week the Queen grabbed headlines by commenting that the Financial Services Authority had got "a bit lax" during the banking crisis of 2008.
"The Financial Services - what do they call themselves, the regulators - Authority, which was really quite new... it didn't have any teeth," she said.Suggest a correction