The Prime Minister has revealed that he finds talking politics with the Queen very useful as she is "always" up to speed and has "heard it all before".
Discussing his weekly Buckingham Palace audiences with the monarch, David Cameron divulged that he was very aware the Queen has worked with 11 Prime Ministers before him.
"You are very conscious as Prime Minister that I am her 12th," he told BBC Radio 2's Steve Wright Show.
"She started with Winston Churchill and she has heard it all before. I think prime ministers find it very valuable to try and explain the difficult decisions and problems the country faces in the presence of someone who's heard and seen all these problems before," he added.
Cameron also said the Queen was "always" up to speed, adding "you have to make sure you are well-informed too if I can put it that way".
David Cameron today pledged to "work really hard" to win back voters who abandoned the Conservatives for the Ukip as Nigel Farage's party made a series of stunning gains in the council elections.
The UK Independence Party leader claimed a "sea change" in British politics as they gained 131 council seats - far more than predicted - while securing second place in the South Shields parliamentary by-election.
Having previously derided Ukip as "fruitcakes, loonies and closet racists", the Prime Minister adopted a notably more emollient tone, promising to show "respect" for those who voted for them.
However he immediately came under pressure from Tory right-wingers to firm up his commitment to a referendum on Britain's EU membership in a bid to counter their appeal.
David Cameron's messages of support to Britain's sporting superstars have not always delivered the luck in which he intended.
In recent times a string of athletes have seen their hopes of sporting glory fade following endorsement from the Tory leader.
The Prime Minister sent his best wishes to Britain's number one female player Laura Robson, 19, shortly before her fourth-round exit at Wimbledon.
Last summer he arrived at Wimbledon for the finals, where Murray was defeated by Roger Federer, and he followed this with a series of visits to Olympic events where British medal hopefuls lost out.
David Cameron will risk the wrath of Tory backbenchers by making the European Union a key part of his vision for Britain's future.
The Prime Minister is to stress the importance of being at the "top table" in institutions such as the EU, saying membership is in the national interest.
The intervention comes in a speech in Essex tomorrow, billed as setting out the UK's role in the world ahead of the G8 conference in Northern Ireland.
Mr Cameron will argue that the Government is in a "battle for Britain's future", blaming Labour for "passing the buck".
He will acknowledge the pain of austerity, but insist the country has started reforming "just in time" with a "complete plan for national renewal".
Mark Thatcher has expressed thanks for the "warm" messages of support received in the wake of his mother's death.
He said: "These messages often convey personal stories and vignettes of part of the journey of my mother’s life and we are all enormously grateful for the warmth that these messages of convey and they will be a source of encouragement and strength as we face the inevitable days ahead.
"And for that I am most grateful."
Mark Thatcher has paid tribute to his mother and expressed thanks for the messages of support.
Mark Thatcher says his mother would be "humbled" by the presence of The Queen at her funeral.
He added: "I would like to say how enormously proud and equally grateful we are that Her Majesty has agreed to attend the ceremony next week in St Paul’s and I know my mother would be greatly honoured as well as humbled by her presence."
Sir Mark Thatcher said his mother Baroness Thatcher would be "greatly honoured as well as humbled" by the Queen's presence at her funeral next week.
Green Party MP Caroline Lucas said she would prefer to spend time in Brighton than pay tribute to Baroness Thatcher.
The Labour MP for Rotherham Sarah Champion said Thatcherism "tried to destroy our town".