Rachel Reeves will meet with fuel bosses today telling them motorists must get a “fair deal” amid the fall-out of the Middle East conflict.
The Chancellor insists she will not stand by if firms use the Iran war as cover to hike prices at the expense of drivers.
She will host a roundtable with petrol retailers and energy suppliers in Downing Street this evening.
Reeves will put them on the spot to demand what they are doing to keep the pump prices down.
Figures from the RAC show petrol prices per litre are up more than 7p and diesel is up 15p per litre since the start of the conflict.
She said: “I will not tolerate any company exploiting the current situation to make excess profits at consumers’ expense.
“I’m backing drivers and families — and I expect a fair deal at the pump.”
It comes after she warned retailers about price gouging as prices go up.
The Chancellor along with Energy Secretary Ed Miliband will demand to know why prices vary so widely across the country.
She told MPs this week that prices varied per litre from £1.27 to £1.80 across forecourts.
Brent crude oil rose by 9 per cent on Thursday but then fell back to less than $100 a barrel.
Major supermarkets are now providing prices to the Fuel Finder scheme to help track prices.
Whitehall officials believe the increased transparency could see motorists save £40 a year when filling up.
It comes as The Competition and Markets Authority told firms responsible for thousands of fuel stations that it was bringing forward formal requirements to supply revenue, costs and sales data.
Their chief executive Juliette Enser, said: “Whilst price increases might be inevitable because of rising wholesale costs, it is important that those increases reflect genuine cost pressures.
“We will be closely scrutinising and reporting on what’s happening with fuel prices and call out any concerning behaviour.”
Meanwhile, Kemi Badenoch filled up a lorry with diesel yesterday as she calls on the government to keep a 5p fuel duty discount.
The Tory leader used a visit to a machinery firm in Wembley to demand the current cut is maintained beyond September.
She has said that motorists are being used as a “cash cow” and has demanded Labour doesn’t scrap the fuel duty hike.
Ministers have been under huge pressure to keep the reduction as households struggle with rising pump prices.
The Chancellor said this week that she was “loath” to spend taxpayers’ cash on extending the discount. Sir Keir Starmer said the increase was “under review”.
