Opposition Leader Bill Shorten has labelled the prime minister a "coward" and says the government's decision to delay the sitting of parliament is an "assault on democracy".

The House of Representatives was due to return on November 27 for the final sitting fortnight of the year.

But Leader of the House Christopher Pyne said the Senate was unlikely to finish debating same-sex marriage laws - the government's priority for the final sittings for the year - until November 30, so there was no point in the lower house sitting next week.

Mr Shorten said Malcolm Turnbull was running scared from the parliament, with the Coalition was two MPs short due to by-elections.

"If you cannot control the parliament, you cannot control the country," Mr Shorten said today.

"This is an assault on democracy."

Mr Shorten slammed the prime minister for using the Senate debate on same-sex marriage legislation as a reason for delaying the parliamentary sitting.

"He is a coward when he hides behind marriage equality," Mr Shorten said.

Queensland MP Bob Katter is lobbying colleagues to have parliament sit next week - with or without the Liberals.

Only the Speaker of the House of Representatives has the power to postpone parliamentary sittings, but Mr Katter foreshadowed plans to go rogue.

"Whether it sits on the garden lawn or whether it sits in the building, we don't care. It will vote. It will make the laws of the land," Mr Katter told reporters in Townsville.

"We'll form parliament, we'll appoint a speaker and we'll proceed.

"If the Liberal Party choose not to turn up, well, that is their choice."

Mr Katter says he has contacted Greens MP and fellow crossbencher Adam Bandt with his plans to travel to Canberra for the scheduled sitting.

Former Nationals leader Barnaby Joyce is expected to be returned at the December 2 by-election in his NSW seat of New England and would not be available for a parliamentary sitting week starting on November 27.

There are also fears the government could lose the seat of Bennelong, held by Liberal John Alexander, to Labor after the opposition preselected former NSW premier Kristina Keneally for the December 16 by-election.

A renewed push for a banking commission of inquiry is also weighing heavily on Mr Turnbull, as Coalition backbenchers move closer to getting the numbers for what could be an embarrassing defeat for the government which has long opposed such an inquiry.

Mr Pyne said the decision had nothing to do with numbers on the floor of parliament, as he did not expect the official writs to have been returned for the New England by-election in the week starting December 4.

In any case, the government had the support of crossbench MPs Cathy McGowan and Rebekha Sharkie for confidence and supply.

He said the government wanted not only to pass the same-sex marriage laws but deal with the MP citizenship issue before the year's end.

"That is the commitment we have made and that is what the Australian people expect," Mr Pyne said.

The lower house will resume on December 4 at 10am, and will immediately pass a resolution setting a December 5, 8pm, deadline for citizen disclosures.

Then it will move onto debating and passing the marriage equality bill and any amendments.

Any referrals to the High Court resulting from members' disclosures will be debated after the passage of the bill.

Mr Pyne said MPs should be prepared to sit for some or all of the second week starting December 11.

The Liberal frontbencher also appeared to give some leeway to Labor MPs who have faced Coalition calls to resign over accusations of covering up problems with their dual citizenship.

Asked whether in-doubt MPs would be allowed to vote on same-sex marriage in coming weeks, Mr Pyne said: "Every member of the House of Representatives is eligible (to vote) until the High Court says they are not - that is the precedent and that is the precedent we will be following."