Peta Credlin Chief of Staff to Tony Abbott.

Peta Credlin Chief of Staff to Tony Abbott. Photo: Andrew Meares

Senior Coalition minister Mathias Cormann has urged unnamed colleagues to "back off" from making attacks on Prime Minister Tony Abbott's chief of staff Peta Credlin in the media.

''The people that are briefing [the media] are disgruntled people," Senator Cormann said on Sunday.

The West Australian senator said Coalition MPs should be thanking Ms Credlin for the central role she played in getting them into power, rather than resorting to cowardly and anonymous attacks in the media, he said.

"[The] people that are out there briefing against her in the shadows should just back off," he said.

Fairfax Media has been told that Immigration Minister Scott Morrison was chided by Ms Credlin as they left a cabinet meeting last month.

In the exchange Ms Credlin spoke about Mr Morrison's poor performance at a news conference.

Cabinet sources said Mr Morrison did not take the criticism well and expressed his frustration that he was not allowed to say much at his weekly media appearances.

Mr Morrison's spokesman said the account was ''complete rubbish''.