Motorists have been warned about the rising cost of diesel at the pump, which is "perilously close" to reaching £2 per litre.

RAC fuel spokesman Simon Williams said wholesale costs mean pump prices are “on course” to move closer to the milestone.

Figures from data firm Experian show the average price of a litre of diesel at UK forecourts reached a new high of 197.1p on Tuesday.

The average price of petrol was a record 189.3p per litre, which the AA branded “a disgrace”.

Twelve months ago the prices were 133.5p for diesel and 131.1p for petrol.

Bradford Telegraph and Argus: Petrol prices at Wetherby Services on June 8, 2022 (PA)Petrol prices at Wetherby Services on June 8, 2022 (PA)

The Competition and Markets Authority announced last week that it will carry out a “short and focused review” of fuel prices after a request by Business Secretary Kwasi Kwarteng.

Mr Williams said the price of diesel is “perilously close to the £2-a-litre milestone”, with the cost of a full tank for a 55-litre family car exceeding £108.

He went on: “With the oil price falling and wholesale costs down over the last week, pressure is mounting on the biggest retailers to turn the tide and put petrol pump prices into reverse.

“It now seems we’ve reached the current petrol peak, so we expect to see the big four supermarkets start to cut their prices.

“As they dominate UK fuel retailing this should lead to others reducing their prices too, which will benefit drivers everywhere.

“The situation with diesel is different, unfortunately, as wholesale prices last week still put it on course to move closer towards an average of £2 a litre.

“If, however, oil continues to trade lower it could just prevent this from becoming a reality.”