Boris Johnson praises David Cameron's 'schmoozathon' in Europe
Boris Johnson has "reminded" David Cameron that he should be prepared to campaign for the UK to leave the European Union, if talks on renegotiating the terms of membership are unsuccessful.
In his first formal speech in the Commons since returning as an MP, he said: "I think all of us would want to remind the prime minister and our negotiators... that if you are going to go into a difficult international negotiation of this kind, then you have got to be prepared to walk away if you don't get the result that you want."
He also told MPs he thought that Mr Cameron's "schmoozathon" with other EU leaders would be successful.