A supermarket chain is slashing the cost of petrol to less than £1 a litre... but there’s a catch.

Morrisons – which has three petrol stations in four Hertfordshire – will allow customers spending more than £50 to take advantage of their special offer.

The discount will take the price down to as little as 99.9p a litre.

Those with diesel vehicles will also be able to save paying just over £1.

It’s the first time since the Brexit vote fuel has been this cheap.

According to petrolprices.com average petrol and diesel prices have hovered above the £1.10 mark since June. The current average for unleaded is listed as just above £1.15-a-litre.

Morrisons have fuel filling stations at their stores in: St Albans, Borehamwood and Welwyn Garden City, The offer runs until December 3.

Roger Fogg, services director for Morrisons, said: “With Christmas around the corner, our customers tell us they very much welcome our help in reducing the cost of their fuel. That’s why we are turning the clock back to the start of this year when petrol prices were typically below £1 a litre.”

Last week Asda, Tesco and Sainsbury’s cut their prices by 3p a litre.