The lobby group Fair Fuel UK wants the Chancellor to scrap the planned August increase in duty by 3p in his Budget later this month.
Last week the average price of a litre of unleaded petrol hit 137.44p, a new record high.
It's predicted that could reach 142p by Easter. Diesel currently costs a record 144.67p and could reach 150p by April.
The AA's Edmund King tells ITV Wales of "an almost 20% rise" in the cost of petrol compared to two years ago.