He told the phone hacking trial jury “I don’t want to minimise it or excuse it – it was wrong and it should not have happened.”

But the father-of-three denied prosecution claims that the fling between the two former News of the World editors must have lasted more than six years.

Coulson said it had only been two brief affairs with a long period in between when they were merely good friends.

He also refused to accept the allegation that it had involved them both in breaching professional standards.

Coulson, who later became David Cameron’s spin doctor, said that he had first got to know Brooks in 1996 and they became colleagues on the Sun two years later.