Tony Abbott has heaped praise on Malcolm Fraser describing him as a fine Liberal prime minister and a distinguished leader of the party.
The opposition leader was responding to reports that Mr Fraser, who was prime minister between 1975 and 1983, has quit the Liberal Party.
Mr Fraser resigned in December, saying the party was no longer a liberal party but a conservative party, The Australian Financial Review said on Wednesday.
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While he got on personally with Mr Abbott, Mr Fraser saw the current Liberal leader as "all over the place" on policy, the paper said.
Mr Abbott said he was not prepared to say anything negative about Mr Fraser.
"I think he was a fine Liberal prime minister," he told Macquarie Radio.
"He was a distinguished leader of our party through some difficult times as well as some successful times."
Mr Fraser "obviously" had a right to make judgments about where he stood these days.
"I thought that the most interesting thing that Malcolm Fraser's done recently, though, was declare that the Rudd government was worse than the Whitlam (government)," Mr Abbott said.
But Liberal backbencher Jamie Briggs was more critical, comparing Mr Fraser to former Labor leader Mark Latham.
He wouldn't say if he was disappointed by Mr Fraser's decision because he didn't know the man.
"(But) I guess it's the same, you can ask the Labor party members if they're disappointed Mark Latham's no longer a member of the Labor party," Mr Briggs told reporters.
Greens: Resignation a 'turn off'
Greens leader Bob Brown said the resignation would be a turnoff for many a Liberal voter.
"If they're losing a great Australian like Mr Fraser from their ranks, then there'll be many other Australians who would be Liberals who will be looking elsewhere," he said.
"It's a commentary about the Liberal Party having drifted so far away from its roots."
Liberal MP Petro Georgiou, a former Victorian state director of the Liberal Party, said he was deeply saddened by news of Mr Fraser's resignation.
"Malcolm's made an enormous contribution to Australia and to the party," he told ABC radio.
"He's shown that it's possible to be very politically tough but also compassionate and have a real social conscience."
Mr Fraser was a person who took his personal convictions very seriously, Mr Georgiou said.
"Malcolm's had a classical Menzian view of the party and has been troubled by where he's seen the party go over recent years.
"I think it is a general view by Malcolm that the party differs from the party that he joined."
