David Cameron has been told he should be "ashamed of himself" as he was heckled during a speech to mark one month to go until the Olympics.

Just seconds into the address to London 2012 employees, the Prime Minister was shouted at by the protester.

The man cried: "Shame on you, David Cameron - you are crippling the poor in London. Shame on you."

He tried to carry on but was ushered out of the room and drowned out by other volunteers.

Mr Cameron responded by saying: "This is not about politics. This is about Britain. It is about volunteering. It is about our country. It is about a successful Olympics."

A London 2012 spokesman said: "People are allowed their political views. It was just a rather inappropriate place and time to air them."