The RAC said the average price of petrol jumped to £1.51 a litre on Sunday, while diesel increased to £1.55.

The price of both fuels has jumped since Thursday, when Russia began its assault on Ukraine.

RAC fuel spokesman Simon Williams said despite oil prices calming, prices at the pump will continue to rise.

The cost of filling a 55-litre family car with unleaded petrol is now £83, or £85 for diesel.

"This week will be an important one in terms of the oil price as it's likely to reveal the speed of the inevitable upward trend or the extent of the volatility in the market," said Mr Williams.

The price of Brent crude rose by 4.6% to $102 barrel on Monday after Western nations imposed new sanctions on Russia - one the world's largest energy producers.

Petrol price movements in the UK are mainly determined by the price of crude oil, and the exchange rate between the dollar and the pound, because fuel, like oil is traded in dollars.

Although the UK imports just 6% of its crude oil from Russia, it would still be affected by global wholesale prices rising.

Prices were above the average at a Shell garage in West Yorkshire on Monday

UK consumers are already paying a high price for fuel, with demand surging following the easing of Covid restrictions.

Steve Irwin, from fuel consultancy firm Portland, told the BBC that prices had risen due to concerns over oil and gas pipelines which travel through Ukraine and carry Russian products.

He said there was "potential for enormous supply disruption" if Russia retaliated to sanctions and used oil "as a weapon".

"It's impossible to know what kind of trajectory we are looking at for oil prices over the coming weeks," he said.

However, Mr Irwin added that price was a bigger concern than supply currently, as the US and Saudi Arabia are also huge oil exporters.

'What do you put first? Food, heating or petrol?'

Mandy Watts is limiting how much she drives because of the price of fuel

Mandy Watts depends on her car for work, but thinks "the cost of petrol has gone through the roof".

Going carless isn't an option for Mandy, but she is trying to use it less.

"Being a single parent as well, you have to think about these things," she told the BBC.

"Is it petrol, is it food, is it heating, what do you put first? Food and heating has to come before petrol. So I tend to limit a little bit where I go now."

'A silver lining'

Robert Halfon, a former Conservative minister, has called on Chancellor Rishi Sunak to look at reducing VAT or fuel duty, which has been frozen for 12 years.

He told the Times: "Given what is going on it is genuinely going to be unaffordable for most families. It isn't just for motorists, it's businesses too because they can't afford transportation costs and things like that."

Luke Bosdet, fuel spokesman for the AA, said the rise in fuel costs came at the same time as households were facing energy bill rises.

"To think that, less than two years ago, fuel at £1 a litre beckoned," he said.

"If there is a silver lining, the predictions of 160p or even 170p-a-litre fuel now look exaggerated as the oil price fell back after one day's surge last week."