Queensland cancer patients will be able to access specialist treatments at a new $750 million centre, which is expected to ease pressure on crowded public hospitals.

Premier Annastacia Palaszczuk on Monday announced the new Queensland Cancer Centre at the Royal Brisbane and Women's Hospital will receive funding in next Tuesday's budget.

She said the facility will offer diagnoses, treatments and outpatient services to thousands of cancer patients every year.

"It's like a one-stop shop for the most sophisticated treatment that people need all under one roof, this is exactly what the doctor ordered," Ms Palaszczuk told reporters on Monday.

The facility will have 150 beds, 26 consulting rooms, 37 chemotherapy chairs, four operating theatres, plus pathology services and a pharmacy.

Those new beds are expected to relieve some pressure on public hospital emergency departments, which have been struggling with acute capacity problems for years.

"So they (cancer patients) won't be presenting to emergency, they'll be coming here," Ms Palaszczuk said.

"So they'll be easing the pressure on our emergency departments."

Construction work is set to begin in 2024 and take about four years, with some services coming online prior to completion of the project.

Treasurer Cameron Dick promised funding for frontline health care would not be cut in June 21's budget, amid mounting pressure from COVID-19 and influenza outbreaks.

Mr Dick previously promised to cut $44 from household electricity bills this year with a one-off rebate costing $385 million.

Another $200 million will go into a fund for new roads, sewerage systems and other infrastructure in the southeast of the state to spur new housing developments.

Public high school students are to have access to free period products, while $72 million will go towards a new aeromedical hub at Brisbane Airport.

All up, Mr Dick said he expects to spend about $1.5 billion more than the government earns in his 2022/23 budget.

That is about $900 million lower than the deficit he forecast six months ago, partly due to rising taxes on coalminers and gambling firms.

The government is also expected to start pocketing interest earnings from tenants' rental bonds from July 1.

The treasurer promised not to hike any taxes, fees or charges at the 2020 election, but now insists that pledge was made to families, not businesses.

"We didn't make a promise to big corporations, whether they be in Queensland or national or multinational," Mr Dick told reporters on Monday.

"We didn't make a promise to them. We didn't make a promise to big coal corporations. We didn't make a promise to big offshore-based online betting companies.

"Those companies have made billions of dollars since we made that promise, billions and billions, and it's about time Queenslanders got their share of that in the future."