Senior coalition minister Mathias Cormann has urged unnamed colleagues to “back off” from their destructive media attacks on the Prime Minister’s chief of staff Peta Credlin.

“The people that are briefing are disgruntled people,” Senator Cormann told Fairfax Media on Sunday. “They are certainly not interested in maximising our chances of success in the future”.

Mutual loyalty: Prime Minister Tony Abbott, then opposition leader, speaks to his chief of staff Peta Credlin in Parliament. Credit:Alex Ellinghausen

Senator Cormann, the Finance Minister and one of the most powerful figures in the Abbott government, came to the defence of Ms Credlin, who has been criticised by coalition MPs as a “control freak” in anonymous briefings to journalists.

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 anonymous attacks through the media.