MILLIONS of British Gas customers were today urged to consider switching suppliers after the energy giant announced record price increases.

The group said gas bills would soar by 12.4% and electricity bills by 9.4% to compensate for higher wholesale energy prices.

The increase - taking effect from September 20 - will add £99 to the annual fuel bill for a family of four buying both gas and electricity from British Gas.

It is the second increase in a year from British Gas following a 5.9% hike in January.

Critics attacked the scale of the increases and warned vulnerable customers would be hit.

Jennifer Evans, from price comparison website uSwitch.com, urged the 18.4m British Gas account customers to consider switching supplier for a better deal.

But she warned: "We have already seen a couple of other suppliers implement their second price rise of the year.

"But when British Gas announce an increase, the rest normally follow suit."

One group likely to be badly hit is the elderly.

Many struggle to meet fuel bills - especially in winter- and there are fears more will suffer.

Jean Lorriman, a spokeswoman for Huddersfield and District Pensioners, said: "It is an horrendous increase.

"Pensioners struggle as it is and old people will try and economise even more. I fear it is going to lead to more deaths from the cold."

The increases mean gas customers will see their bills rocket by almost one-fifth in less than a year.

A couple in a three-bedroom house, will face a rise of £74 a year, according to uSwitch.com.

The increase is the highest by British Gas since the gas market was opened to competition in the mid-1990s.

Mark Clare, managing director of British Gas, said the increases were due to rising oil prices and the UK's need to import large amounts of gas following a rundown in supplies from the North Sea gasfields.

British Gas said it had pledged £10m to set up a fund to help "vulnerable" people pay their bills.

Allan Asher, chief executive of gas and electricity watchdog Energywatch, called the increases "a body blow" to consumers.

He said: "This price rise is going to add millions to bills and expose many thousands of households to the risk of fuel poverty.

"We can welcome the move to set up a fund to help consumers in difficulty of paying for their energy, but overall this is seriously bad news for millions of consumers."

Energywatch said it would be calling for an investigation into the wholesale market.

How to change

CHANGING power suppliers is easy.

Several organisations can offer help, including energywatch - on 08459 06 07 08 or at energywatch.co.uk - Power.co.uk and uSwitch.com

Power companies can also be contacted direct for quotations on the full details of their own pricing structures.