Liberal MPs are reacting furiously to the Prime Minister's claim that internal critics of his powerful chief of staff are sexist, with one questioning her influence over the Prime Minister.

But junior minister Jamie Briggs has hit out at his "gutless" colleagues for taking their complaints to journalists instead of directly to Ms Credlin.

"If they've got any balls, they would go and talk to her herself," he said on Friday.

Tony Abbott strongly defended "The Chief" on Friday and in a television interview with the ABC asked if she would be coming under attack if her name were "Peter" instead of "Peta".