David Cameron Explains Why He Agreed To Nelson Mandela Selfie With Obama And Thorning-Schmidt

David Cameron has offered up an excuse for why he decided to take part in the now infamous selfie photograph with Barack Obama and Danish prime minister Helle Thorning-Schmidt during Nelson Mandela's memorial service on Tuesday.

The prime minister told MPs today: "When a member of the Kinnock family asked me for a photograph, I thought it was only polite to say yes."

Thorning-Schmidt, the Social Democrat leader of Denmark, is married to Stephen Kinnock - the son of former Labour leader Neil Kinnock.

The three world leaders have been criticised by some for having fun during the service held to mark Mandela's death. Michelle Obama also looked less than impressed.

Cameron told the Commons during prime minister's questions today that perhaps he should "remember the TV cameras are always on".