The Prime Minister is facing a revolt by Conservative backbenchers calling for plans to raise fuel duty to be binned.
MPs are to vote on a backbench motion calling on the Government to align the fair fuel stabiliser with a "price stabilisation mechanism".
The stabiliser was brought in by George Osborne in the Budget, and now 83 Tory and five Lib Dem MPs are among those who have signed the latest motion for a further measure.
The motion, signed by more than 100 MPs, goes against coalition policy.
However, there has been no word from the Government over whether Conservative MPs will be advised to vote against it.
The debate comes after more than 100,00 people signed a petition over the matter. The debate was secured by Tory MP Rob Halfon, who said there would be a three-line whip.
The Times reported that the Government was weighing up abolishing the proposed rise, which would see an increase of 3p a litre in the new year.
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