Boris Johnson will not be sacked from the Tory frontbench over allegations he had an affair, David Cameron has said.
Boris Johnson is Tory higher education spokesman
The Tory leader said he had spoken to Mr Johnson, who is in China on a fact-finding mission, and reassured him he would keep his job.
"I have read the newspaper headlines. I think it is a private issue," he told London radio station LBC.
"My judgement has to be on how Boris is doing his job and that is what I will stick to," he said.
"It is all about how he is doing his job. And I think actually he is doing his job well."
Mr Cameron said politicians "are all human, we all are flesh and blood and make mistakes" and should be judged on "whether they are honest and straightforward in their dealings with colleagues and whether they are straightforward with the public".
"People have tough things in their private lives they have to sort out and I hope Boris will sort it out," the Tory leader went on.
"Marriages do break up and people do things that they should not, but that should not mean necessarily they lose their jobs."
According to press reports at the weekend the Henley MP, who is the Tory higher education spokesman, had an affair with a 29-year-old journalist.
The married father-of-four was sacked from the Tory frontbench by Michael Howard over an affair with Spectator columnist Petronella Wyatt.
Mr Howard felt Mr Johnson had misled him over the affair, although the MP denied lying to the leader's office. Mr Johnson was brought back to the frontbench by Mr Cameron after he gave up his editorship of The Spectator magazine, pledging to concentrate on politics.