Following npower's decision to raise its energy prices, consumers have been advised to switch to a better deal.
According to moneysupermarket.com, energy prices now vary across the UK for npower's customers.
The firm noted that those in the north of England can expect to pay approximately £100 more than customers in Scotland.
Additionally, customers in London saw a 21.7 per cent increase in prices, while people in the north-west are likely to pay 20 per cent more.
Paul Schofield, head of utilities at moneysupermarket.com, said that people ought to think about switching providers as they "don't want to wait in a rising market".
Adam Scorer, director of campaigns at energywatch, said that the next few months could see thousands of customers "wonder how they can afford to keep their homes warm".
"Consumers need energy authorities and Government to act to ensure that competition works for consumers, not gas producers, and that the most vulnerable consumers are given adequate protection," he argued.
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