It is hard to see why next week’s sitting of the House of Representatives in Canberra has been cancelled unless it is out of sheer panic.

On Monday morning, backbench Nationals senator Barry O’Sullivan, a power broker in the Liberal National Party in Queensland, declared war on Malcolm Turnbull.

The heavyweight senator, who sits as a National in Canberra, went on the airwaves to declare the Turnbull government was out of touch on the banks and that he was organising a private member’s bill to set up a commission of inquiry.

The numbers are already in the Senate for such a move. A Greens bill sailed through the chamber earlier in the year.

Senator O’Sullivan is now counting on two Nationals in the lower house, George Christensen and Llew O’Brien, to accommodate his push in the absence of two MPs caught up in by elections – Barnaby Joyce and John Alexander.

Just in case you missed the missile aimed at the bows of the government, Senator O’Sullivan says “if it’s good enough for conservative governments to have royal commission into trade unions, pink batts and detention centres then it is good enough to have one for the banks as they are more corrupt than the unions and on a scale much bigger”.

In a clear indication that Senator O’Sullivan knows his actions are damaging for Mr Turnbull, he defends them in terms of salvaging credibility for the Nationals anticipating an election loss.

He says “we have been loyal members to the Coalition but now we have to look after the National Party so we are there in the future”.

So just when you thought Malcolm Turnbull would be given time to capitalise on his significant win in the marriage equality survey, the divisions that have hamstrung him in the top job are back with a vengeance.

And don’t forget the context in Senator O’Sullivan’s home state of Queensland. It is the final week of the state campaign where the LNP is locked in a tight battle with Labor and Pauline Hanson’s One Nation.

The House of Representatives will not return until December 4. Photo: ABC

Word from the campaign trail is Labor is firming in the race. If it scrapes across the line get ready for the Turnbull government to get blamed.

Then there is the issue of same-sex marriage legislation itself. It is a free vote, but Senator O’Sullivan and fellow conservatives are lining up behind Liberal defector Cory Bernardi’s push to heavily amend their colleague Dean Smith’s bill.

Scarcely hiding the hint of payback it is all in the name of religious protections.

This completely unmasks their ploy of foisting a plebiscite on Mr Turnbull. It was just a weapon to frustrate the Prime Minister’s agenda. Never mind it was also frustrating the majority will of the people.

The decision to cancel next week’s scheduled sitting is aimed at minimising the government’s vulnerabilities on the floor of Parliament and to hide behind the Smith bill.

Labor is accusing the Prime Minister of cowardice and undermining the democratic process. There is no doubt he and Christopher Pyne have the legitimate ability to shut down Parliament. But it in turn raises questions about their political judgement and nous.

There are 53 pieces of legislation that are waiting to be debated, including anti-money laundering measures and counter-terrorism amendments.

Mr Pyne insists it is all about focusing the Parliament on marriage equality and dealing with the citizenship eligibility of politicians.

Labor, the Greens and some crossbenchers say they will come to Canberra anyway, to work.

The Senate will sit as scheduled. The Reps face a lockout. The TV pictures won’t be pretty for the Prime Minister.

Paul Bongiorno AM is a veteran of the Canberra Press Gallery, with 40 years’ experience covering Australian politics.