THREE of the UK s big four supermarkets have been found to be raising fuel prices by nearly three times as much as necessary, but where can you get the cheapest petrol in Gwent? Sainsbury’s, Morrisons and Tesco have been accused of exploiting drivers, having all increased prices by an average of 3p per litre in December, despite the wholesale cost of fuel only rising by around one pence. Only Asda, which added around 1.5p to its prices matched the wholesale increase. The RAC’s fuel spokesman Simon Williams said that the supermarkets appeared to be trying to protect themselves from a possible drop in income during the latest lockdown.