PRIME Minister Tony Abbott has raised the prospect of an early election if key Budget measures are blocked in the Senate and has warned minor-party senators they are likely to lose their seats at an early poll.

Key crossbench senators yestserday said they would oppose contentious measures announced in the Budget, including the introduction of new medical fees and changes to pensions.

Labor plans to vote against “broken promises’’, including the debt levy and fuel excise increase.

Mr Abbott said a certain amount of horsetrading was inevitable in politics but warned independents and minor parties against frustrating the Government’s agenda.

“I don’t believe that they will try and completely frustrate the business of government because if there was an election again, hardly any of them would win their seats,’’ the Prime Minister told Sydney radio 2GB.

Mr Abbott was optimistic the Government could persuade minor party senators to support its reforms.

“I think in the end they will sit down with the Government and work out a way of getting this legislation through,’’ he said.

Incoming South Australian senator Bob Day said he would oppose increases in fuel excise and the debt levy on incomes over $180,000.

“I’d vote against all tax measures because they don’t work,’’ Mr Day said.

Mr Day said he was also opposed to the $7 Medicare co-payment because families were already struggling with cost-of-living pressures. But he praised the Government for cutting spending in the Budget.

Independent SA Senator Nick Xenophon backed the debt levy on high-income earners but was concerned about other measures in the Budget.

“I think it has been a ham-fisted Budget,’’ Senator Xenophon said.

“It doesn’t seem to be a Budget which thought through the implications it will have on ordinary families.’’

Clive Palmer said his Palmer United Party would lead community resistance to many of the changes announced in the Budget and had nothing to fear from an early election.

“I think for honesty in government an election is not uncalled for because people thought they were voting for one thing and (got) something else,’’ Mr Palmer said.

Mr Palmer dozed off during question time after earlier using a lunchtime address to supporters to accuse the Government of starving the states of funds so that they would have to privatise services.

“They’re putting pressure on the states to sell our hospitals, sell our schools,’’ he said.

The Greens will support the re-indexation of fuel excise but oppose the debt levy.

It is not yet clear which Budget measures could be included in appropriation bills in order to make it difficult for the Senate to block them without forcing the entire government to shut down.

When asked about the possibility of a double dissolution election if the Government could not get its Budget reforms through the Senate, Treasurer Joe Hockey said it was a matter for the crossbenchers.

“Look, that’s up to them, the crossbenchers. I don’t have the capacity to psychoanalyse them. I would not encourage anyone else to try,” Mr Hockey said.