The government has already postponed it once, but Sustrans is urging Westminster to resist delaying a rise in fuel duty again next January.
Petrol prices were due to rise three pence this summer, but Chancellor George Osbourne postponed that until the start of next year. Now motoring groups are lobbying for the rise to be cancelled entirely.
According to the charity Locked Out, 35 million people in England are facing the prospect of debt just from getting around. The Department of Transport's own 2011 Travel Survey found that over a quarter of British families are already without a car.
Sustrans said that by sticking with the petrol tax increase the money could then be used to invest in transport investment that will benefit everyone.
Joe Williams, Policy Advisor for the charity Sustrans, said, “The cost of car ownership, increasing public transport fares and a lack of safe walking and cycling routes has already ensured that millions of households are trapped in transport poverty.
“We cannot pretend that relying on universal car ownership to allow people to access jobs, schools and healthcare is feasible given that the cost of petrol will continue to rise in the long-term irrespective of fuel duty levels.
“Fuel duty rises must continue in order to help Britain recover economically and fund a transport system that enables everyone to get around, including investment in reliable and affordable public transport and the provision of safe walking and cycling routes.”
Previous anecdotal evidence has found that 'petrol pump crises' have seen a rise in bike riding. In the warmer weather, at least.