John Healey was today facing growing calls to abandon Labour’s planned Fuel Duty raid if Downing Street is serious about helping hard-pressed families with the cost of living.In a private letter to the Chancellor, industry chiefs warned pump prices were on the rise again and could remain high for months as the Iran war drags on.It came as analysis found sky-high prices have collectively cost families embarking on their summer holidays £500million at the pumps since schools broke up last month.Prices soared again today, with petrol hitting a new post-war record, making a fill-up £15 more expensive compared to before the conflict.Since the war began on February 28, it has cost drivers an estimated extra £5.5billion at the pumps, with the Treasury in turn raking in nearly £1billion more in VAT.This is because the 20 per cent levy accounts for a larger slice into Treasury coffers when petrol and diesel are higher.But despite this windfall, Fuel Duty is set to be hiked by 3p a litre on New Year’s Day and a further 2p on March 1, netting billions more for the Treasury. John Healey was written to by the Petrol Retailers Association, which warned of high pump prices for some time and called for him to scrap Labour's planned Fuel Duty raid Pump prices soared again today, with petrol hitting a new post-Iran war record, making a fill-up £15 more expensive when compared to prices before the conflict The Iran war has dragged on after a tentative peace deal between US President Donald Trump and Iran broke down last month, with Western oil supplies continuing to be hit Mr Healey and Prime Minister Andy Burnham have so far slashed VAT on household energy bills. But critics point out this has only saved families on average around 86p a week.In the letter to Mr Healey, seen by the Mail, boss of the Petrol Retailers Association (PRA) Gordon Balmer urges him to go further by using his first Budget this Autumn to freeze Fuel Duty beyond January to help motorists make ends meet.It states: ‘The ongoing conflict in the Middle East continues to cause extreme fluctuations in the price of crude oil and the wholesale cost of petrol and diesel.‘Unfortunately, January and February are precisely the months when household budgets are typically at their most strained…we welcome the focus you have announced on making life more affordable and bringing down the cost of living for ordinary people.‘That is why I am today asking you to abandon your plans to end the Fuel Duty cut at the start of 2027.‘By doing this, you can help motorists, businesses, and ordinary working families by providing them with confidence that you are doing what is within your power to support them.’The PRA represents more than 5,000 forecourts across the UK. The Tories' shadow transport secretary, Richard Holden, added: 'Labour’s Christmas holidays fuel tax hike will hurt businesses and hammer hardworking families already stretched to breaking point.'For months, Conservatives have been calling for Labour to axe their fuel tax hike.'Andy Burnham must not target drivers to fund his eye-watering spending plans; plans that can only be paid for through tax rises.'It’s time for Andy Burnham to rule out a fuel duty tax hike.'It comes amid growing fears of wider tax rises after Mr Burnham went on a spending spree during his first days as PM, making nearly £2billion-worth of unfunded commitments. Average pump prices surged again today, rising to 160.85p a litre for petrol and 180.34p for diesel Before the Iran war, average petrol prices were 132.83p a litre and diesel was 142.38p, meaning a fill-up is £15 and £20 more respectively than before the conflict Fuel duty is currently frozen at 52.95p a litre until January, having not risen for more than a decade.A 5p a litre cut in the levy introduced by the Tories in 2022 is set to expire on January 1.Average pump prices surged again today, rising to 160.85p a litre for petrol and 180.34p for diesel. This was the highest post-Iran war price for petrol.Both fuels dipped after a US-Iran ceasefire was announced in June.But after the conflict flared up again when the tentative deal broke down last month, prices have been back on the rise.Before the Iran war, they were 132.83p a litre and 142.38p, meaning a fill-up is £15 and £20 more respectively with both fuels than before the conflict broke out.This adds nearly £500 to the average family’s annual diesel bills and nearly £400 for petrol, based on the average family filling up twice a month.Analysis by the RAC Foundation shows that since July 17, when the great summer getaway started as schools broke up, sky-high pump prices have cost motoring families £500million when compared to prices before the war started.It means the Treasury has raked in an extra £80million in VAT this summer alone and £920million since the conflict started because of higher prices at the pumps.Treasury sources said a decision on Fuel Duty would not be made until Mr Healey's first Budget, on October 28.Simon Williams, the RAC’s fuel guru, said petrol prices may stabilise in the coming days as wholesale prices have fallen. But diesel prices are expected to continue soaring.He added: ‘The news for those who rely on diesel, including many businesses, is worrying as it looks set to carry on rising, possibly reaching 185p in the next week or so.’The Treasury was contacted for comment.