“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”.

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.

“People that are out there briefing against her in the shadows should just back off,” Senator Cormann said.

Fairfax Media has been told that Immigration Minister Scott Morrison, who has been running tightly controlled weekly briefings about the Coalition's ''stop the boats'' policy, Operation Sovereign Borders, 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 during a recent news conference.

According to cabinet sources, Mr Morrison did not take the criticism well and expressed frustration that he was not allowed to say much at his press appearances.

According to one source who witnessed the exchange, Ms Credlin shot right back at Mr Morrison with: ''We will tell you what you can say and what you can't say.''

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

The office of the Prime Minister described the account of the meeting with Mr Morrison as "untrue".

In a rare public outburst last week, coalition Senator Ian Macdonald used a speech in the senate to complain of a culture of ''obsessive centralised control'' exercised by Mr Abbott's office.

Coalition MPs have privately expressed similar concerns after Senator Macdonald's accusations that ''unelected advisers in the Prime Minister's office'' were meddling too much in the minutiae of day-to-day proceedings.

Senator Cormann said the bitter MPs were criticising Ms Credlin for simply doing her job, which was to ensure the government worked as efficiently as possible and the best possible candidates were selected as staff for MPs.

“Peta Credlin has done an outstanding job for us in opposition,” Senator Cormann said. “She’s been central to get us back into government… She obviously has a very important job at the heart of the government and she will be central to our success”.

Ms Credlin has been Tony Abbott’s most trusted confidant since he took over as opposition leader in the lead up to the 2010 election.

Ms Credlin has been widely credited for coordinating a highly effective office and media strategy. She is seen by many as the most capable political operator in the Abbott government and on election night Mr Abbott described her as “the smartest and fiercest political warrior” he has known.