Prime Minister Malcolm Turnbull is facing the biggest threat to his leadership since taking over as leader of the Liberal Party in 2015.

There is speculation Home Affairs Minister Peter Dutton could challenge Turnbull for the Liberal leadership, amid concern over the government’s National Energy Guarantee.

“I enjoy the confidence of the cabinet and of my party room,” Turnbull told reporters in Canberra on Monday.

Asked whether he had spoken with Dutton, the prime minister said his cabinet colleague was at the leadership group meeting on Monday morning and had attended cabinet last night.

“He is a member of our team. He has given me his absolute support.”

So, why am I suddenly seeing “leadership spill” everywhere all over again?

The coalition’s primary vote has dropped from 39 to 33 in just a month, according to the latest Fairfax/Ipsos poll published on Sunday night.

Labor leads the coalition 55 per cent to 45 per cent on a two-party preferred basis.

The Australian reports that rebellion on the Liberal backbench spread over the weekend as ministers struggled to achieve internal consensus on the National Energy Guarantee.

The public divide has lead to speculation Dutton may make a move for the Liberal leadership with the support of conservative party members.

The speculation gathered steam after a radio interview last week where Mr Dutton said further disagreements could lead to his resignation from cabinet.

He took to Twitter on Friday to “make very clear” that the prime minister had his support as did the policies of the government, but The Australian claims a number of MPs called Dutton over the weekend to pledge their support should he challenge Turnbull.

Okay then, so why is Dutton the one tipped to challenge Turnbull for the leadership?

Quite simply, because he can.

Dr Zareh Ghazarian, a political scientist from Monash University’s School of Social Sciences told Mamamia that leadership challenges happen because the system allows it.

In 2013, Kevin Rudd left Labor a parting gift of rules designed to stop constant leadership changes. The Liberals, however, are still traditional in the sense that the party’s members of parliament vote for their leader.

Dutton represents a much more conservative Liberal Party than Turnbull, whose policies have been very much based on socially progressive ideals.

“Dutton represents Liberal MPs who were supporive of Tony Abbott and have been feeling disappointment with Malcolm Turnbull’s leadership and policy portfolio,” Dr Ghazarian said.

“I think this challenge, if it is coming, is not about the National Energy Guarantee alone. This is the last straw for many of these MPs. Turnbull has lost their support because of a whole list of policy decisions made that they would oppose.”

Another reason Dutton is seen as the most likely to mount a challenge is because he is a well-recognised figure from Queensland. In order to win the next election, the government will need to defend eight marginal seats in the state, including Dutton’s own seat of Dickson.

Many within the party see a Dutton leadership as the best bet to hold these seats.

What the heck is the National Energy Guarantee?

The National Energy Guarantee, known as the Neg, is a policy that planned to impose two obligations on energy retailers: an obligation to supply sufficient quantities of reliable power to the market and an obligation to reduce emissions between 2020 and 2030.

On Monday Turnbull outlined a raft of major changes to his energy policy, including abandoning plans to legislate carbon emission targets.

Critics of the policy were deeply unhappy with the 26 per cent reduction target contained in the Neg, and Turnbull said this was scraped because it would not have passed the House of Representatives due to opposition from members of his own party.

He has rejected claims that changes to the policy are aimed at holding off a leadership challenge.

Monash University's Dr Ghazarian told Mamamia the way in which Turnbull has sought to address energy pricing and climate change "is clearly unacceptable to others in this party".

Dr Ghazarian believed Turnbull's concessions on this policy show he is taking this leadership challenge very seriously.

"It is an attempt to appease those trouble makers in his own party, to keep them on side and stop them from mounting a challenge."

How likely is it this is going to happen?

Well, it's pretty likely. And it'll probably happen quickly, too.

Though Dr Ghazarian isn't confident that Dutton has the numbers required to win a leadership challenge, this could all change rapidly and we'll likely have an answer in 24-48 hours.

"When it gets to these sorts of things it's just hour by hour. Every phone call, every meeting will be treated with cynicism."

"Based on the last leadership spill, Tony Abbott had around 30-40 MPs in his corner. I expect Dutton to have at least the same amount."

He said Dutton will be counting on waverers to back him over the coming hours and days.

Regardless of the outcome, Dr Ghazarian believes it is too late for the Liberals to maintain a sense of party unity heading into next year's election.

"I don't think [Turnbull] has had party unity from the day he took power, but all he can do is make concessions to these MPs... His job is just to limp to the next election if he survives this week."

So what would a leadership change mean for everyday Aussies?

If Dutton mounts and wins a challenge, he will become Australia's sixth prime minister in 11 years.

Dr Ghazarian told Mamamia though the public are not involved in choosing the leader of a party, they don't necessarily approve of leadership changes during a term.

"The public vote in governments and they know who the leader is," Dr Ghazarian said. "If they are voting in the government I think the public want the opportunity to vote out a government as well."

Dutton also represents a far more socially conservative arm of the Liberal Party, which could mean a change in Liberal policy and a much more conservative focus in the lead up to the election.

He is mostly recognised for his tough stance on immigration. He opposed same-sex marriage, however voted in favour of the Marriage Amendment (Definition and Religious Freedoms) Act 2017, after 65% of his constituency voted yes in the postal survey.

Dr Ghazarian said many of Dutton's policies could be used a "pay back" to Turnbull, shifting the Liberal party much further to the right.

What is the Turnbull camp saying?

• "I enjoy the confidence of the cabinet and of my party room," Turnbull told reporters in Canberra on Monday.
• "I don’t believe there’ll be a challenge to Malcolm Turnbull’s leadership. I believe that the cabinet is 100% behind Malcolm Turnbull, including Peter Dutton. He’s a very valued colleague, a good friend, he’s very competent. I don’t believe he’s doing anything to change the leadership of the party," said Sturt MP Christopher Pyne.
• "I would urge everybody else - the hanful of individuals who cause trouble - to think about the consequence of continuing to cause that trouble... it's literally only a handful of individuals who decided to try to derail those policies," Education Minister Simon Birmingham told Sky News.
• "The prime minister has my support," said Craig Kelly, the MP for Hughes.

What the Dutton camp is saying.

• Over the weekend, Tony Abbott reportedly told a Young Liberal event in Tasmania that he looked forward to serving under a Dutton government. Abbott has since said: "It is not about him, it is not about me ... the only way we can win the election is to have a contest on policy.

With AAP.