Thousands of people will have to pay higher gas and electricity bills after a company announced increased charges.

Seeboard gas and electricity prices are to rise for the sixth time in two years, this time by almost 15 per cent and five per cent respectively, next month.

Customers and energy watchdogs reacted angrily, saying they were concerned that higher bills will lead to tighter budgets and leave many in poverty.

A spokesman for Energywatch said: "For many hundreds of homes they are going to have to make the decision whether they heat themselves or eat. This is the sort of choice we are looking at.

"The Government says for every one per cent that fuel prices go up, around 40,000 homes go into fuel poverty across the UK and prices are now at a level where they are threatening to completely derail the Government's ambitions to eradicate fuel poverty."

The rises mean that for a typical household, bills will rise by almost 30p a week for electricity and just over £1.32 a week for gas.

Pensioner Jean Fowler of Tower Road, Lancing, a Seeboard electricity customer, said the news had made her determined to change to a cheaper supplier.

She said: "If it's going up even more it's terrible. Energywatch told me about a cheaper place and I had never got around to changing but I definitely will now.

"I haven't got central heating so it's quite cold in my house but I can't afford it. My children keep on at me to do less work because I'm 73 in March but how can you afford to with everything going up?"

Seeboard, which is owned by EDF Energy, supplies about 1.7 million customers in the South East.

Derek Lickorish, chief operating officer of EDF Energy Customers Branch, said: "With soaring wholesale energy costs, we have been forced to raise our prices.

"However, through ownership of our own generating capacity, we have been able to limit the overall rise for all our customers."

Earlier this month The Argus reported that British Gas looks set to increase its prices by up to 25 per cent.

And in August last year we reported that EDF Energy was hiking its prices for the fifth time in 18 months.

Customers on capped or fixed rates will not be affected by the rise as their bills are protected until 2007 and 2008 respectively.