By Kat Wong and Jack Gramenz in Canberra

The prime minister hopes the budget cycle will force the opposition to show its cards as he confirmed Australians would go to the polls in May.

Ahead of the budget on Tuesday, the federal government has spruiked its cost-of-living relief efforts, announcing a $150 energy bill rebate in an extension of the $300 subsidy offered in the previous budget.

Though Opposition Leader Peter Dutton has called the plan a “Ponzi scheme”, the coalition revealed it would support the measure, drawing criticism from the government.

“The rhetoric that they use in attacking this means that they can’t be secure,” Prime Minister Anthony Albanese told reporters in Canberra on Monday.

“Having opposed all of these things for almost three years – just to have said ‘yes’ – they’ve got to have something to say about policy and they don’t have any of their own.

“I look forward to some policy… coming out sometime between now and May.”

The opposition leader is promising a major announcement in Thursday’s budget reply speech with immigration and housing likely to be areas of focus.

Recent migration intakes had forced Australians out of the housing market while not enough homes were being built, Mr Dutton claimed.

“It’s meant that people are lining up for longer and paying more for rental properties,” he told reporters.

“It means that Australians have just given up on the dream of home ownership.”

Shadow treasurer Angus Taylor has declined to say whether the coalition will stick with its previously-outlined target of reducing net overseas migration by 25 per cent.

Treasurer Jim Chalmers said the government was “managing” migration down and recent figures showed about 10,000 fewer people had arrived than anticipated.

“The budget will update all of those forecasts but what they will show overall is the trajectory is down. That’s deliberate,” he told Sky News.

The opposition is already expected to take public service cuts, nuclear power and tax deductions to the election with the prime minister widely tipped to visit the governor-general by Sunday to fire the starting gun for an early May poll.

Recent YouGov polling showed Mr Albanese consolidating his lead as preferred prime minister, but still predicted a tight election with voters evenly split between Labor and the coalition once preferences are factored in.

Crossbench senators Jacqui Lambie and David Pocock will on Monday call for gas exports to be diverted to the domestic market.

“Most of our gas goes overseas and makes a bucket load of money for shareholders while Aussie businesses and householders are struggling to pay their power bills,” Senator Lambie said.

“It’s time to stop protecting the gas cartel and start protecting Australians.”