More than 50 Tory MPs have banded together to demand a cut in fuel duty in the Autumn Statement next week.
MPs, which include six government ministers, authored the letter to chancellor Philip Hammond to warn consumers and businesses are being ripped off at the petrol pumps.
Campaigners argue that even if fuel duty increased in line with the RPI next April, it would equate to an £40,000 increase in costs for an average haulage business.
And they add that consumers have not benefited from a 4p drop in wholesale prices, with a muscular new watchdog needed to make sure that savings are passed on.
MP Charlie Elphicke, who chairs the all-party group on fuel costs, said: “The fuel duty freeze has been of real benefit to the UK economy. But it’s clear that cutting fuel duty would be an even bigger boost to hard- working families and small businesses.
“We must build a Brexit Britain that works for every family, every small firm and every driver. A Britain that works for everyone must include a fair deal on fuel prices.”
Elphicke added that a new “PumpWatch” regulator should be able to levy fines for predatory pricing.
FairFuel UK campaigner and motoring journalist Quentin Willson said: “We shouldn’t allow fuel retailers to make opportunistic profits and the government needs to reduce their tax take and support these silent wealth creators. No other country burdens business transport like this.
“It’s time the government talked less about cyclists and more about the tens of millions of drivers who literally drive the economy.”
Hammond is due to to deliver the Autumn Statement on 23 November.