Labor is poised to kill the marriage equality plebiscite when federal parliament returns this week – with a final decision of the caucus due on Tuesday.



The Turnbull government will want to use the resumption of parliament after a three-week break to direct the political focus onto its industrial relations agenda – including legislation associated with the Country Fire Authority dispute in Victoria.

One Nation is also expected to reveal its position on the double-dissolution election triggers, the restoration of the Australian Building and Construction Commission, and the registered organisations legislation, over this coming week.

But the government’s efforts to move forward will be complicated by the almost certain defeat of the plebiscite, and the renewed political pressure the Coalition is likely to face about the banks after three days worth of hearings with chief executives in Canberra last week.

The government will take various marriage amendments to its party room this week, including a proposal allowing celebrants and ministers to refuse to officiate at gay weddings if they object on religious grounds – but these protections are not expected to be extended to service providers, like wedding cake makers or florists.

The comparatively limited nature of the exemptions from anti-discrimination law will likely not please everyone in the Coalition party room, even if the amendments ultimately prove to be hypothetical because of parliamentary opposition to the plebiscite.

Coalition sources have indicated privately they could have objections, depending on the detail of the proposal the attorney general, George Brandis, brings forward this week.

Arriving at the Canberra airport ahead of the new sitting week, Brandis launched a final appeal for Labor to support the plebiscite, saying it was the most immediate mechanism to deliver marriage equality. Brandis said if the issue was not resolved now, the debate would drag on for “years”.

“If Labor thinks this debate is divisive, why not get it over and done with,” he told reporters in Canberra on Sunday.

The Greens have flagged they will move to introduce legislation to the Senate this week that would set up a parliamentary commission of inquiry into the banks.

Greens finance spokeswoman Sarah Hanson Young said the inquiry would have similar powers to a royal commission, but it would not require endorsement from the executive.

The government is attempting to stave off pressure for a royal commission by drawing attention to its plans to establish a new banking tribunal to hear complaints from aggrieved customers.

Over the past week, to send a positive message about its responsiveness during the banking hearings, the government has made it known that the tribunal will work like an expanded ombudsman for aggrieved customers, so banks will not be able to appeal the tribunal’s decisions.

The banking industry will be required to pay for the new body. But the tribunal proposal is not expected to be finalised until next March.

Labor is yet to make a decision on whether or not to support the Greens proposal on the parliamentary inquiry for the banks, but the opposition will attempt to broaden the conversation about the banks to economic management in the wake of the treasurer Scott Morrison’s trip last week to New York, where he met ratings agency S&P.

The shadow finance minister Jim Chalmers said on Sunday the final budget outcome had confirmed a $35bn blowout in the deficit, and a $77bn blowout in net debt since the Coalition took office.

Chalmers said the chief economist of the National Australia Bank, Alan Oster, had warned that any downgrade of Australia’s triple-A credit rating would increase the wholesale funding costs for the banks by between 10 and 20 basis points, with flow-on consequences for home mortgages, which could see interest costs increase by more than $700 a year.

Chalmers said Labor, which agreed in the last parliamentary sitting week to the government’s omnibus savings bill, with measures worth $6bn, would “continue to lead the conversation when it comes to budget repair and will continue to provide the economic leadership the government has proved incapable of.”

On Sky News on Sunday, the finance minister Mathias Cormann said the Coalition had stabilised government spending. “So instead of continuing to increase – as was the trajectory under Labor – we have been able to stabilise it, and are now projected to bring it down.”