Before Friday, the price cap meant the average household’s annual energy bill was between £1,277 ($1,676) and £1,370. Under the new price cap, millions of households could see their energy bills rise by around £700 a year.

According to the Resolution Foundation’s briefing on Friday, low-income households would be hit hardest by the price rise, with the poorest 20% of households set to spend 10% of their budget on energy bills, while the wealthiest 20% of households would spend 4% of their budget on energy.

Prices in the U.K. are increasing after wholesale natural gas prices reached record highs in Europe last year, caused by a number of issues including low inventories and Russia tightening its gas supply to the EU even before disputes over energy purchases that have arisen since Moscow’s invasion of Ukraine.

The U.K. has been hit particularly hard by the wholesale gas price surge, due to its heavy reliance on gas as an energy source, and the issue has heavily contributed to the country’s worst cost of living crisis in decades.

British Finance Minister Rishi Sunak announced in February that all residential electricity customers would receive a £200 discount on their electricity bills from October, which would later be repaid in £40 installments over five years.

He also announced that the majority of households would be given a £150 rebate on their council tax — a levy paid by households based on the value of their home.

The war in Ukraine, and the Western sanctions package that has been imposed in response, has already created volatility in energy markets, and could threaten more price and supply instability in the future.

With Russian President Vladimir Putin locking horns with European leaders after demanding payments for Russian gas be made in rubles, some energy analysts have warned that European countries — including the U.K. — could be forced to resort to rationing supplies of natural gas and diesel if Russia decides to shut off its supplies to the continent.

Putin issued a warning in recent days that if “unfriendly” countries refuse to make payments in rubles by Friday, their contracts for gas purchases would be halted — a move condemned by Germany, Europe’s biggest consumer of Russian gas, as “political blackmail.”

While the price of natural gas has fallen drastically in Europe since earlier this month, prices remain inflated.

The increased supply should help push prices down since more than 50% of the cost of gasoline is based on the price of oil, according to the U.S. Energy Information Administration.

Expect prices at the pump to fall “maybe a penny every day or two,” said Patrick De Haan, head of petroleum analysis at GasBuddy.

“We could see the national average price of gasoline fall back under $4 a gallon in the few weeks ahead,” he said. “Diesel should fall back under $5 a gallon nationally, as well.”

However, the exact impact on prices will be determined by the amount of oil purchased in the market and how long the daily releases go on, according to AAA.

Still, “the global oil market remains highly volatile, so additional news that threatens supply could put upward pressure on oil prices,” AAA also said.

Already, the national average for a gallon of regular gasoline fell two cents this week to $4.22.

Now, nearly 9 in 10 car owners are concerned about being able to afford filling up, according to a separate report by AutoInsurance.com.

To shield yourself from unpredictable prices at the pump, consumer savings expert Andrea Woroch has these tips:

• Track gas prices. Apps like GasBuddy, Gas Guru and AAA TripTik can track down the cheapest price per gallon between gas stations. Even if the difference doesn’t seem like much, it can add up to hundreds of dollars a year.
• Pay with cash. The price per gallon can be 10 cents to 15 cents more per gallon for credit card transactions. Pay with cash instead to get the lower price or use a gas rewards credit card to earn cash back on those charges. (CNBC’s Select has a full roundup of the best the best cards for fueling up based on your consumer habits.)
• Drive strategically. Carpooling to and from work and school or sports practice can dramatically reduce your time on the road. You can even find ride shares using sites like ZimRide, RideJoy or eRideShare.com, Woroch advised. Also, order online and look for free delivery to cut the cost of getting groceries, takeout and other daily essentials.
• Sign up for loyalty programs. In addition, loyalty programs, which many major gas station chains have, can help offset the price at the pump. Some grocery store chains may also offer cents-per-gallon rewards. For example, Kroger and Shop & Stop give fuel points for every $1 spent on groceries, which can be redeemed at participating gas stations.