The government may unpick another aspect of the budget by reversing proposed new duties on motorists and hauliers already hit by rising fuel prices after Gordon Browns ministers yesterday paved the way for a new tax retreat.

While hundreds of lorry drivers blockaded streets in London, ministers signalled that Chancellor Alistair Darling would take pity on road users when he draws up his pre-budget report in the autumn.

Members of Mr Darling’s team said he was “listening carefully” to Labour MPs and others on whether to press on with plans to increase fuel duties by 2p a litre in the autumn and for a controversial reform to vehicle excise duty.

Having already been forced to water down his plans to reform capital gains tax, the chancellor held an emergency £2.7bn mini-budget, this month, to compensate losers from the abolition of the 10p tax band.

However, as fuel prices soar and household budgets tighten, Mr Darling’s aides insist he is “very aware” of concerns raised by Labour MPs and motoring organisations. The chancellor’s team realise that any retreat on the road tax plans in particular would be seen as another humbling U-turn.

But one of Mr Darling’s allies said: “If it’s the right thing to do, he will do it.”

According to Grant Thorton, the accountants, if oil prices stay at their current highs due to North Sea oil revenues, the Treasury could fund the scrapping of the proposed 2p increase in fuel duty and its new tax on larger cars, and still beat the relevant revenue forecasts over this financial year by more than £4bn.

A commons motion calling for rethink on the road tax plan has been signed by 35 Labour MPs. The plan - under which larger family cars, including models bought since 2001, would see a sharp rise in vehicle excise duty. Labour MPs have claimed that the plan to increase taxation for older family cars would hit poorer families and undermine the government’s claim to be on the side of hard-working households in difficult times.

Insiders at Downing Street say a retreat on the VED plan was not under “active consideration” but pointedly refused to say whether it would survive in the chancellor’s autumn pre-budget report. Under the plan, cars with higher emission levels would be charged a higher level of road tax.

Justice Secretary, Jack Straw said in an interview, “The chancellor and prime minister have said quite explicitly we are listening to public concerns about this and – if there are going to be decisions announced – they could be announced in the autumn.”

John Hutton, business secretary said, “The chancellor is listening to what people are saying about VED, as he has done on a number of occasions recently about tax rises.”

Labour MPs are now expected to scrap completely, the proposed 2p fuel duty rise, which was proposed by Mr Darling by six months until the autumn.

Across Europe, the impact of rising fuel prices is a growing problem. Yesterday, French president Nicolas Sarkozy, suggested a cap on sales taxes on fuel to try to hold prices down.