Petrol prices hit a record 185p per litre on Sunday, as ministers asked for an urgent review into whether the fuel duty cut is being passed on to drivers.
But the AA said petrol pump prices "should be grinding to a halt, at least temporarily, by the end of the week", as wholesale prices flatten.
Soaring fuel prices have been driven by the war in Ukraine and moves to reduce Europe's dependence on Russian oil.
Motoring groups have called on the government to do more to help drivers.
The RAC said a further cut to fuel duty would be "very welcome, albeit overdue".
"The speed and scale of the increase is staggering with unleaded going up 7p in a week and diesel by nearly 6p," the group's fuel spokesman Simon Williams said.
