Opposition Leader Tony Abbott has asserted his plan to reduce government spending by as much as $47 billion should he triumph in the next election.

Discontinuing the federal government's computers in schools program, privatising Medibank Private, crossing out the National Broadband Network, and slashing 12,000 jobs from the public service will be among the repercussions.

"We are $57 billion in deficit now, which is an absolute record deficit," Mr Abbot said.

According to him, countries including Australia had to reduce their expenditures, or run the risk of "ending up like Greece", which has been pushed to the brink of default.

"Too many countries for too long have been on this debt-fuelled spending binge," he said.

A plan drafted by Mr Abbot and colleagues Joe Hockey and Andrew Robb will reduce spending by $47 billion.

"We are not going ahead with the National Broadband white elephant," Mr Abbott repeated.

"We are going to put the private back into Medibank Private.

"We are going to trim the public service by 12,000.

"We are not going to go ahead with the remaining computers in schools program because at the rate Julia Gillard was rolling the computers out in schools, the kids would have left university before they finally got their computers in schools."

Despite the cuts on spending, however, Mr Abbott has recommitted to his plan to pay businesses to reduce their carbon emissions. While this policy would cost $3.2 billion over four years and more than $10 billion by 2020, the plan would be "prudent and achievable" and would achieve a 5 per cent reduction in carbon emissions by 2020, he said.