Fuel retailers have failed to pass on savings in the wake of an oil price slump, new figures show.
Forecourt prices for diesel could be slashed by around 4p per litre while 2p could be taken off unleaded because oil has remained below 50 US dollars a barrel since June 2, according to the RAC.
The motoring group's fuel spokesman Simon Williams said: "We have been monitoring supermarket fuel prices closely since the oil price began to tumble hoping that we would see them come down, but sadly that has not happened yet. In fact, one even increased prices by half a pence a litre."
Since May 24, wholesale prices for diesel have reduced by more than 3.5p per litre for diesel, with unleaded down 2p.
Mr Williams added: "We sincerely hope the reason that retailers have not passed on savings in the wholesale price to motorists at the pumps this week is nothing to do with them thinking that people are distracted by the General Election."
The average price of diesel and unleaded at the UK's four major supermarkets is £1.14 per litre.
The RAC said the fall in the price of oil was fuelled by the US having more oil and petrol supplies than expected, demonstrating that production cuts from oil producing group Opec are not having the desired effect of reducing output.