Prime Minister David Cameron's official spokesman earlier declined to comment on whether the Government might back down on the 3p fuel duty rise.
He said the controversial rise was a matter for the Chancellor.
Shadow chancellor Ed Balls said George Osborne had been making "nods and winks" on fuel duty over the past 24 hours to dissuade Tory MPs from joining Labour in voting against the 3p rise today.
Shadow Chief Secretary to the Treasury Rachel Reeves has told Daybreak that a delay in fuel duty rise will "make a difference to people".
George Osborne will come under fresh pressure today to scrap January's planned 3p a litre increase in petrol duty. Daybreak's Gregg Easteal reports:
The campaign group FairFuelUK previously said it believed the tax hike could will raise only £800 million, compared to Treasury projections that it would bring in £1.5 billion.
It could also cost as many as 35,000 jobs, it said.
The group will be campaigning at parliament today ahead of the debate and vote in the Commons.
Its spokesman, broadcaster Quentin Willson, said: "The momentum building up behind FairFuelUK's call to see this damaging 3p rise scrapped is becoming unstoppable.
"The Treasury appears to be listening. We welcome Labour pushing on this issue. Consumers are currently paying an eye-watering 80p-per-litre in combined fuel duty and VAT.
"This is socially unjust and adding another 3p in tax doesn't make sense for economic recovery and deficit reduction."
Labour had hoped some campaigning Tory backbenchers would support its motion and rebel against the Government.
But Robert Halfon MP, who has led the campaign against increasing fuel duty, said he would not vote against the Government until he had seen whether George Osborne responds to mounting concerns in the Autumn Statement, due on December 5.
He said: "The cost of fuel is the number one issue, that's why I am campaigning on it.
"I have had discussions with various people and it is my view that the Government is in strong listening mode.
"If I didn't believe that I would make a point and go in to the lobby with Labour."
There was growing pressure today on Chancellor George Osborne to abandon the Government's controversial 3p-a-litre increase in fuel duty planned for January.
Labour are calling on the Government in a Commons vote this afternoon to delay the tax hike until at least next April, claiming families and businesses are in desperate need of some good news from the Exchequer.