The Transport Minister says changes to road user charges for plug-in hybrids are about finding a balance.

Owners will pay $38 per 1000 kilometres- down from a proposed 53.

The amendment put forward by Labour was accidentally agreed to by governing MPs in a mix-up during the select committee stage.

Minister Simeon Brown says this change recognises that hybrids can run on a battery, or on petrol.

"The reality is, this is a tricky issue. There are a range of particularly older plug-in hybrids, which do consume a lot of petrol- and so they would be paying even more."

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