While most of his Coalition colleagues have defended Tony Abbott’s right to voice his opinions as a backbencher, at least one MP has called on the former prime minister to resign over his constant criticism.

In an opinion piece for News Corp that dominated Easter Monday news coverage, Mr Abbott warned that voters believed Bill Shorten was on track to become PM and outlined his own five-point policy plan.

And while a succession of Turnbull government ministers and MPs chose not to attack their former leader, long-serving Federal Member Warren Entsch called on Mr Abbott to quit Parliament if he can’t stop criticising the Government.

“He will either be remembered for his positive contributions in his term as a prime minister or, I am fearful that he will eventually end up being remembered as a spoiler,” Mr Entsch told the ABC.

He reminded Mr Abbott that when he lost the leadership he promised he would not snipe.

“He was going to step down graciously, he was going to serve in the best interests of the country, but he was not going to do a running commentary, he was not going to be critical,” Mr Entsch said.

“Well it has been anything but that.

“I find it very disappointing, it seems to me that it is more about payback for our current Prime Minister.”

Other Coalition figures were more circumspect in their public attitudes to Mr Abbott’s vocal musings.

Speaking on ABC Radio on Monday night, Resources Minister Matt Canavan said that while he didn’t agree with Mr Abbott’s manifesto, he “completely accepted Tony’s right to comment on these matters”.

“He’s been a strong and powerful contributor to the public policy debate over many years,” he said.

Trade Minister Steven Ciobo also earlier said Mr Abbott was entitled to float his own policy ideas.

“I wouldn’t say to any backbencher that that’s a bad idea,” he told ABC Radio.

“Every backbencher has a right to put in their view, that’s exactly how our system works. I encourage every backbencher to keep contributing to the arsenal of policy ideas that the Coalition government has.”

Victorian Liberal Senator James Paterson and NSW Liberal MP Craig Kelly both said Mr Abbott was entitled to put forward his views as a backbencher.

“Truth is, Tony is a backbencher and like any backbencher he is free to make the case for his ideas as often as he likes and however he likes,” Senator Paterson told Sky News.

“Obviously as a former prime minister, his ideas might generate a bit more attention than my ideas or the ideas of my other backbench colleagues. With that extra power comes extra responsibility … I’m sure he’s very mindful of that.”

Tony Abbott says voters told him Bill Shorten will be the next PM. Photo: AAP

Earlier, the former PM wrote that most voters he met while on the Pollie Pedal long-distance charity ride around NSW held an “expectation that [Bill] Shorten could soon be in the Lodge”.

But he added that “the best way to keep Shorten out is not to sack an elected prime minister yet again”.

Monash University political expert Dr Zareh Ghazarian dismissed many Coalition MPs’ suggestions that Mr Abbott was merely sharing his views as a backbencher.

“That’s not an effective line,” Dr Ghazarian said. “He’s just not a backbencher, he’s a former PM.

“Whatever he says and does has a lot of weight and gravitas. It’s a folly to say he’s just like another backbencher. They’re kidding themselves.

“This is yet another way to remind people that he’s around.”

Mr Abbott complemented the op-ed with a doorstop interview and an appearance on 2GB’s Ray Hadley program.

“The truth is, people aren’t happy. They’re more disillusioned than ever with the political class,” Mr Abbott told the radio host.

Mr Abbott’s five-point plan to regain voters’ trust included Senate reforms, ditching wind power subsidies, axing the Human Rights Commission, making it “easier for future generations to get work”, and “don’t apologise for Australia, celebrate it”.

The Sydney shock jock recently announced that the Member for Warringah would become a new fortnightly contributor after Treasurer Scott Morrison was spectacularly dumped from the spot last week.