British Prime Minsiter David Cameron has made his first live appearance on a US chat show, appearing on The Late Show with David Letterman to an audience of some three million.

It all started well for the PM, who managed to talk politics and pay homage to the Olympics with his host.

As he loosened up, however, the PM turned to baiting the American political system over their funding, with Mr Cameron saying: "I've never remarked 'My name is David Cameron, and I approve this messsage'."

He wasn't quite so cocksure when it came to British history though - the PM fell flat in Letterman's citizenship test when he failed to name the writer of Rule Brittania, or translate Magna Carta.