Cameron lays down a friend for his life..
Mr Mercer said of the black men he had known in the Army: "They prospered inside my regiment, but if you'd said to them 'Have you ever been called a nigger,' they would have said 'Yes.'
"But equally, a chap with red hair, for example, would also get a hard time - a far harder time than a black man, in fact."
Mr Mercer added: "But that's the way it is in the Army. If someone is slow on the assault course, you'd get people shouting: 'Come on you fat bastard, come on you ginger bastard, come on you black bastard.'"
He also said: "I came across a lot of ethnic minority soldiers who were idle and useless, but who used racism as cover for their misdemeanours.
"I remember one guy from St Ann's (Nottingham) who was constantly absent and who had a lot of girlfriends.
"When he came back one day I asked him why, and he would say: 'I was racially abused.' And we'd say: 'No you weren't, you were off with your girlfriends again.'"
After the comments were published, Mr Mercer was asked by his party to resign his frontbench position and did so.
He later told BBC Radio 4's PM programme that in his 25-year military career he had twice come across soldiers claiming racism when disciplined for poor performance.
Mr Cameron said: "The comments made by Patrick Mercer are completely unacceptable and I regret that they were made.
"We should not tolerate racism in the Army or in any walk of life."
He also said: "I was completely shocked when I read the remarks of Patrick Mercer.
Shocked he was!, pass the smelling salts as the poor little metropolitan flower tries to gather his strength to stamp his feet in rage. I wonder what that fat moon-faced mummy's boy Cameron would have been called if he had ever joined up.....
I have read the Times interview from which the quotes were culled; he is responding after the announcement of the formation of a new trade union proposed by Marlon Clancy, a serving soldier who was recruited from the Commonwealth, and so it was entirely appropriate he covered the issue of racism. He made clear his own beliefs but was reporting the truth as he saw it: "I had the good fortune to command a battalion that was racially very mixed. Towards the end, I had five company sergeant majors who were all black. They were without exception UK-born, Nottingham-born men who were English - as English as you and me. They prospered inside my regiment, but if you'd said to them: 'Have you ever been called a nigger,' they would have said: 'Yes.'.
Can you spot anywhere where he expresses a racist view, rather than report other's racist comments? anywhere he shows approval of racism? I can't, maybe he didn't make double plus disapproval explicit but then intelligent people talking to another bright person don't feel the need to go in to paroxysms of racist denial everytime they are talking about racial issues. But no, the slightest mention by a white person of how races are treated in the real world is political suicide unless the appropriate tribute is laid at the feet of the idols of the anti-racist industry.
Iain Dale disagrees and believes his Cameron did the right thing.