Tony Abbott is standing by his powerful chief of staff Peta Credlin despite a damaging new leak revealing a major rift between top Liberal Party officials over her role.

The prime minister insists Ms Credlin’s marriage to the party’s federal director, Brian Loughnane, is not a conflict of interest and he has dismissed the latest leak as a “storm in a teacup”.

In two emails leaked to Fairfax Media, the party’s federal treasurer Phil Higginson wrote that Ms Credlin’s relationship with Mr Loughnane was the “most serious current dilemma” facing the party.

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He wrote that “how this party ever let a husband and wife team into those roles” was beyond him, and that their relationship was causing dysfunction and “wooden and unreliable communication”.

But Mr Abbott downplayed the emails and restated his confidence in the power couple.

He pointed out that Mr Loughnane has been the federal director for 12 years and Ms Credlin has occupied a series of senior positions for various ministers and party leaders.

“So if this is a problem, it’s been a problem for 10 years. In fact it is no problem,” he told Macquarie Radio on Tuesday.

The latest leak has been interpreted as a fresh attack on Mr Abbott’s leadership and comes as he faces renewed pressure from within his own ministry, with another Fairfax Media report claiming seven frontbenchers have effectively put him on notice.

Julie Bishop came out in support of Peta Credlin. Photo: AAP

Despite voting to support Mr Abbott against a spill motion earlier this month, the unnamed ministers are reportedly discussing the timing of a potential move against him.

Mr Abbott dismissed that report too, saying voters are “sick of the internals”.

“Prime ministers are always on probation,” he told the Nine Network.

“There is a sense in which every day you have to perform.”

Mr Abbott did have some good news on Tuesday, with the latest Newspoll showing support for the coalition had risen three points to a four-month high.

However, the government still trails Labor 47 to 53 per cent on a two-party basis, while 77 per cent of those surveyed considered Mr Abbott arrogant.

Senior frontbenchers Julie Bishop and Mathias Cormann defended the performance of Mr Loughnane and Ms Credlin, saying they had both occupied their roles for many years.

Ms Bishop said they had been a “formidable pair” that helped the coalition win government.

“Obviously things are in a challenging situation at present and so it seems that people are pointing the finger at those who, in the past, were being lauded for their efforts,” she told ABC radio.

Responding to the report that frontbenchers were plotting against Mr Abbott, Senator Cormann said the prime minister still had the “strong and united” backing of his ministry.

Ms Bishop, who has been touted as a possible replacement for Mr Abbott, said she was not aware of any frontbenchers planning to move on the prime minister.

“They haven’t spoken to me,” she said.