Speaking on ABC radio on Wednesday, Mr Bandt said a majority was not likely in either the House of Representatives or the Senate, paving the way for his minority party to step in.

"The Greens are on track to be the biggest third party in the Senate ever, and in the lower house," he said.

"No one party is going to have a majority in both houses of parliament after the next election, and the Greens are going to be the most powerful third party."

Mr Bandt is confident about the party's prospects at the May 21 poll, claiming the Greens could pick up three new Senate seats, including one in Queensland.

The Greens are currently polling at 14 per cent of the vote in the Sunshine State, but Mr Bandt said there was potential to win a Senate seat off One Nation.

While there has been a focus on teal coloured independents challenging high-ranking Liberals, Mr Bandt said the Greens would still be the largest group of alternative MPs in parliament.

However, the rise of independent candidates was a positive sign.

"We welcome more voices in the democratic competition, including from these independents, and anything that increases the focus on the terrible climate policies of the government and the opposition," he said.

Mr Bandt's comments came ahead of his address at the National Press Club in Canberra on Wednesday when he will spruik a multi-billion dollar plan to have dental care covered by Medicare.

More than $77 billion worth of dental care would be included, according to a Greens proposal.

This would include basic care and orthodontic treatment, as well as oral surgeries, periodontics and prosthodontics.

"Last time the Greens were in the balance of power, we got dental into Medicare for kids and now we'll finish the job by getting dental into Medicare for everyone," Mr Bandt will say.

"In balance of power, the Greens will tackle the cost of living by getting dental and mental health into Medicare, fixing the housing affordability crisis and wiping student debt."

The Greens say their dental plan, costed at $77.6 billion over 10 years, or around $8 billion a year, will be funded by taxes on billionaires and large corporations.

It wants a six per cent tax on the wealth of Australia's more than 130 billionaires and a corporate "super profits tax", which would force businesses to hand over profits after they make $100 million.

"The Greens will make Clive Palmer pay more tax so you can fix your teeth," Mr Bandt said.

The move builds on a $5.8 billion pledge the Greens took to the 2019 election, which would have provided Medicare-funded dental care to all young people, aged pensioners, full benefit recipients and concession cardholders.

At that election, the Greens scored 10.4 per cent of the national primary vote and Mr Bandt retained the party's only lower house seat of Melbourne.

Australian Associated Press