Student debt handbacks and electric vehicle subsidies will be on the chopping block if the coalition wins the federal election.

Opposition Leader Peter Dutton said earlier this week that he would not repeal a fringe benefits tax break for EVs, which has blown out in cost due to its unexpected popularity.

But the coalition has since revealed they would axe the incentive, putting their leader's earlier statement down to him mishearing the question.

Liberal campaign spokesman James Paterson said Dutton's comments were the result of a misunderstanding.

"From the very beginning, we've been highly critical of this policy," he said.

"We don't think it's a good use of taxpayers' money to subsidise people who can afford to buy a brand new electric vehicle and have everyone else pay for that."

A cornerstone of the coalition's campaign, which has featured frequent petrol station visits by Dutton, has been its pledge to temporarily cut fuel excise.

Labor's $16 billion promise to cut student debt by 20 per cent for more than three million Australians would also be scrapped, setting out another clear point of difference between the major parties.

For a student with the average HECS debt of $27,600, they would see their bill reduced by more than $5500.

The government has argued the measure was aimed at helping students deal with cost-of-living pressures and fixing generational unfairness.

But shadow treasurer Angus Taylor and opposition finance spokeswoman Jane Hume said it was unfair for students who had already paid off their student debt and for tradies, who got nothing from the policy.