Scott Morrison has hinted he could revoke a $200m agreement with Bob Katter for Queensland water projects if the maverick sides with Labor and fellow crossbenchers to support an extension of the parliamentary sitting calendar against the government’s wishes.

With parliament set to resume on Tuesday, and with Labor and several crossbenchers lining up to extend the sitting weeks to allow consideration of the recommendations from the banking royal commission, the prime minister was asked twice on Monday whether Katter would lose his water deal in the event he forced the extension.

Rather than ruling it out, the prime minister said at the National Press Club he didn’t intend to “entertain” the question.

Morrison reached an agreement with Katter last November, in which he agreed to provide $200m for water projects to shore up Katter’s support in the House of Representatives following the loss of the government’s lower house majority.

An exchange of letters between Morrison and Katter at the time made it clear the government expected support during any motions and second reading amendments “that attempt to cause disruption to the good order of the House”.

Katter has not yet stated definitively whether he will support a motion extending the sitting program or not, although he has expressed some interest in doing so. The government opposes the move.

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Last week, the mercurial Queenslander told Guardian Australia there “may be some merit” to extra sitting weeks of parliament to consider banking reforms and he would “seriously consider” it.

Katter complained the former prime minister Malcolm Turnbull had “gazumped the crossbench by putting in a toothless tiger” in setting up a banking royal commission on the government’s terms and wants to see more scrutiny on bank bosses than “little blokes selling mortgages”.

“But the prime minister [Scott Morrison] may threaten to go to the people and dump on us [at an early election] … There’s going to be a lot of brinksmanship here. We’ll see who blinks first,” he said.

Katter’s vote only comes into play if the other House crossbenchers side with Labor on the motion. Government sources are privately confident they have the numbers to repel the sortie.

With the political fight between the major parties escalating, Labor on Monday said it would no longer sign up to pairing arrangements for votes requiring an absolute majority of 76 MPs in the House of Representatives.

The government leader in the house, Christopher Pyne, responded that the “unprecedented” move would prevent members attending to sick family members or getting medical attention.

“The then-opposition never stooped this low even in the darkest days of the 43rd parliament,” he said, although the Tony Abbott-lead opposition was criticised for restricting the practice of pairing.

Christopher Pyne (@cpyne) By cancelling pairs the ALP are saying they won’t let any Member of the HoR leave to attend to a sick family member or to get medical attention themselves. It’s unprecedented and the then Opposition never stooped this low even in the darkest days of the 43rd Parliament. #auspol

The implied threat to Katter was part of a wide-ranging speech from Morrison that focused on amplifying political conflict with Labor over national security.

The prime minister also confirmed the Coalition would announce measures on climate policy before the next federal election – something the government has been telegraphing for some weeks.

Morrison acknowledged that climate change was a factor in the frequency of extreme weather events Australia has experienced over the summer months.

The government is expected, as part of the reboot, to beef up the Emissions Reduction Fund, a vestige of Tony Abbott’s Direct Action program and possibly expand the fund’s remit.

There is also an internal push to increase funding for the Clean Energy Finance Corporation and Arena, as well as craft a package of measures targeted at households.