Britons are now paying over £100 ($125) to fill up an average-sized family car after petrol prices soared past the psychological threshold for the first time ever Thursday.

The price is based on the cost of filling up a 55-litre family saloon — £100.27 — as average U.K gasoline prices surpassed £1.82 a litre. That roughly translates to $8.60 a gallon, with one litre equal to 0.264172 U.S. gallons.

The cost of filling an equivalent car with diesel is £103.43, with diesel now priced at £1.88 a litre.

British automotive company RAC, which provided the figures, said it was “a truly dark day today for drivers” as fuel prices continue to push higher.

“While fuel prices have been setting new records on a daily basis, households up and down the country may never have expected to see the cost of filling an average-sized family car reach three figures,” RAC fuel spokesperson Simon Williams said in a statement.

Thursday’s milestone is latest marker of the continued upward pressure on fuel prices amid Russian oil sanctions and soaring inflation.

The cost of unleaded petrol is now 37% more expensive in the U.K. than this week a year ago, while diesel is 38% more expensive.

The U.K. government announced a 5-pence-a-litre cut to fuel duty in March to help reduce costs for motorists. However, motoring groups have warned that retailers are not passing cuts on and said more support is needed.

“March’s 5 [pence] fuel duty cut now looks paltry as wholesale petrol costs have already increased by five-times that amount since the Spring Statement [25 pence],” Williams said.

“A further duty cut or a temporary reduction in VAT would go a long way towards helping drivers, especially those on lower incomes who have no choice other than to drive,” he added.

Industry analysts are now predicting that petrol prices could rise even higher.

“We are certainly peppering the £2 a litre mark at the moment,” Gordon Balmer, executive director at the Petrol Retailers Association, told Sky News Thursday.

Still, the U.K. is not the most expensive place for fuel in Europe.

Denmark is the costliest country in the region for petrol, according British motoring association the AA. The price at the pump was £2.05 a litre as of 30 May.

It was followed by Greece, Germany and then Britain.

Exchange rates, VAT levels and duty levels are among the reasons for the differing fuel prices across the continent, according to an AA spokesperson.