The threat came as it emerged yesterday that most of the cabinet learnt of the decision to put the ETS on hold until at least 2013 when they read it in the Sydney Morning Herald.

The Prime Minister, Kevin Rudd, is trying to swing the agenda to health. He is demanding the opposition pass a bill to means test the 30 per cent private health insurance rebate that would provide $2 billion over four years and be used to fund the health reforms negotiated with the states.

The means test legislation has been rejected twice and already qualifies as a double dissolution trigger. The government will introduce it for a third time after the May 11 budget to highlight Senate obstinacy over health.

Asked yesterday if a double dissolution election over health was on the cards, Mr Swan said: ''We'll certainly be making sure that we prosecute this issue to the fullest extent.''

But a fellow minister said it would be implausible for the government to call such an election over health when the ETS also qualifies as a trigger.

Mr Swan said that while the savings from the means test were vital to fund the health reforms, the savings made from shelving the ETS were not.

''On budget night you will see that we have funded our commitments in health … and you'll see how we have funded them,'' he said. ''And I can tell you it won't relate to the [ETS].''

Mr Swan also disputed reports that shelving the ETS would save $2.5 billion over four years. Mr Rudd told the Herald last week that the government found the budget savings to pay for the health promises last month, before it shelved the ETS.

''We started detailed work in January-February so we're talking about that time - February-March - that we put it into our budget papers,'' he said.