The rebate allows miners and farmers to claim subsidies for the off-road use of diesel.

Shadow treasurer Chris Bowen has guaranteed Labor won't touch the measure if leader Bill Shorten wins the next election, while addressing the Mineral Council of Australia's tax conference.

"Every so often, in our regular meetings, a resources company will ask me about our plans for the diesel fuel rebate," Mr Bowen has told the event in Perth on Wednesday.

"My answer is pretty straightforward: no change. We won't be making any changes to the diesel fuel rebate if we win office."

Mr Bowen says Labor can make the commitment as it has done the hard yards to propose a series of other tax reforms, such as changes to negative gearing.

"Because we've been upfront about the plans we are seeking a mandate to introduce to fund our important initiatives, we won't need to engage in this sort of knee-jerk ambush of business."

He has also sought to convince miners that Labor has a better plan than the coalition to lift investment and labour productivity nationally.

Such plans include Labor's proposed Australian Investment Guarantee, which would give every business the ability to immediately deduct 20 per cent of any new eligible asset worth more than $20,000.

He has stressed the policy is a point of difference between Labor and the coalition, since the opposition has vowed to back other initiatives aimed at encouraging investment.

They include cutting the company tax rate to 25 per cent for businesses turning over less than $50 million and extending the instant asset write-off for small businesses making investments less than $25,000.

"I know you have to convince internationally-focused boards of the merits of every potential investment in Australia," Mr Bowen said.

"The Australian Investment Guarantee will be of assistance to you in doing so."

Australian Associated Press