The Prime Minister says he replaced Philip Ruddock as chief government whip to allow a "deeper engagement" with his backbench, but the move has rekindled discontent in Coalition ranks.

Tony Abbott made the shock announcement on Friday that he was dumping the veteran MP from the key position in the aftermath of this week's failed attempt to spill the leadership.

On Saturday, Mr Abbott was asked by reporters in Sydney if the move was an act of retribution.

"No, not at all," he replied.

"Philip Ruddock is a friend, Philip Ruddock is a colleague and Philip Ruddock was a supporter.

"But what I am determined to do is have a deeper and stronger engagement with the backbench and that means it was very important to renew and refresh the whips team."

Some of Mr Abbott's supporters believe Mr Ruddock did not do enough to publicly rally support for the Prime Minister and should have done a better job of picking up on backbench disquiet in the weeks leading up to the failed attempt to spill the leadership.

Sorry, this video has expired Tony Abbott comments on the sacking of Philip Ruddock

But some MPs who wanted a spill are bewildered and confused by Mr Ruddock's sacking - one saying "the night of the long knives has begun".

Others described it as "another captain's call" that had gone down badly within the party.

Queensland backbencher Andrew Laming has gone public with his criticism, describing it as "scapegoating of Godzilla proportions".

"We really needed a week of healing, not wounding, and I think it really has set us back a fair bit particularly because Philip Ruddock was such a respected character," Mr Laming told the ABC.

Mr Laming said he spoke to Mr Abbott on Friday and told him what he thought.

"Regardless of the reasons, regardless of what you write in a press release, the perception when acting in this way in this week will be that it was one of recrimination," Mr Laming said.

But Assistant Treasurer Josh Frydenberg said Mr Laming had "ulterior motives" given he supported the spill motion.

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Mr Frydenberg rejected suggestions the Prime Minister's decision was retribution and said he spoke to Mr Ruddock on Saturday morning.

"He understands that this is a decision for the leader to take," Mr Frydenberg told Sky News.

"I think this is a decision that is just within the normal course of what happens within government."

Mr Ruddock is not commenting about the decision, except to say the position of chief whip is the gift of the Prime Minister.

Nikolic says deputy whip position not a reward

Mr Ruddock, who is known as the "Father of the House" for being the longest-serving member of the House of Representatives, will be replaced by Queensland MP Scott Buchholz.

Tasmanian MP Andrew Nikolic, a prominent supporter of the Prime Minister, will also be promoted to a whip position.

He said he did not see it as a reward for publicly urging his colleagues against a spill.

"The reason I did that was not for any reward, but to say to my colleagues that the last thing we should be doing is demonstrating the sort of disunity that the Australian people comprehensively rejected," Mr Nikolic said.

Mr Frydenberg has welcomed the appointments.

"In Scott Buchholz we have a very good man who will be our new whip, and Andrew Nikolic as a deputy who's also very experienced in rounding up the troops if you like," Mr Frydenberg said.

Mr Abbott earlier paid tribute to Mr Ruddock in a statement confirming the changes Friday afternoon.

"I acknowledge and thank the Hon Philip Ruddock MP for his extraordinary contribution to our country, this Government and the Liberal Party," Mr Abbott wrote.

"As Father of the House, Philip has given over four decades of service to the Australian Parliament and the Australian people.

"He was a senior minister throughout the life of the Howard government and was shadow cabinet secretary in opposition.

"Later this year he will become the second longest-serving parliamentarian in our history."

The move had been under discussion for more than a day.

The two men met after Parliament rose on Thursday.