Millions of households face yet more financial misery after two power companies yesterday revealed price rises of up to 29 per cent.

Scottish & Southern Energy  -  which has 8.8million customers  -  is raising the cost of gas by 29.2 per cent and electricity by 19.2 per cent from Monday.

And the 5.5million homes signed up to E.On will see their gas bills go up 26 per cent and electricity prices by 16 per cent from today.

The wholesale price of gas increased by 14 per cent today after a leak caused a pipeline in the North Sea to be shut off

Consumer groups described the latest round of increases as a 'national disgrace'.

A typical family on a dual-fuel contract with see its annual bill soar by £250 a year to more than £1,260.

It follows similar moves from British Gas and EDF last month.

Of the big six energy companies, just nPower and Scottish Power have still to raise prices.

SSE and E.On blamed soaring wholesale gas costs for the latest rise  -  which come at a time of soaring food and petrol prices.

But their announcements provoked an angry reaction from consumer groups, who warned families are already struggling with rocketing household bills.

Running out: Dwindling North Sea energy supplies are a big factor in rising bills

Gordon Lishman of the charity Age Concern said: 'These enormous price hikes will be a huge blow to millions of people already wondering just how they're going to pay their bills this winter.

'We are extremely concerned that the one in three pensioner households likely to be living in fuel poverty  -  defined as having to spend more than ten per cent of household income on fuel bills  -  by the end of the year will feel forced to cut back on essential food or fuel.'

'The Government must seize control of this escalating crisis and take immediate action to ease the pressure on millions of households.'

As well as bringing in fuel vouchers for the poorest pensioners, ministers should force companies to offer social tariffs at the cheapest rates, he said.

Adam Scorer, campaigns director at the independent watchdog Energywatch, said:

'The brakes have failed on the energy market. The results are calamitous.'

This is the second price increase from both companies this year. SSE  -  Britain's second largest supplier and owner of Southern Electric, Swalec and Scottish Hydro Electric  -  last put up its prices in April, when electricity bills rose 14.2 per cent and gas went up 15.8 per cent.

E.On's last increase was announced in February.

It put gas charges up 15 per cent and increased electricity bills by 9.7 per cent.

The latest rises mean SSE customers on a dual-fuel contract will now see their annual bills soar by around £253 to £1,259.

The company's energy supply director Alistair Phillips-Davies said: 'The world is experiencing an energy shock of a kind not seen since the early 1970s, but which is likely to have more profound and lasting consequences.'

German- owned E.On's hikes will see customers who take both gas and electricity paying an average of £1,226 a year  -  an extra £227.

From today, the average annual bill for a customer paying by monthly direct debit will be £1,194  -  up from £967.

Graham Bartlett, managing director of E.On's retail business, said: 'I'm very aware of the effect that today's announcement will have on our customers and I recognise that this is a very tough time for everyone.

'This was not an easy decision to make and we've tried to keep these increases as low as possible while protecting as many of our customers as we can.'

Last month, British Gas announced a swingeing 35 per cent rise for gas bills and nine per cent for electricity, with rival EDF upping bills by up to 22 per cent.

Wholesale gas prices rose yesterday  -  to reach 109p per therm up from 104p  -  following the closure of the Norwegian North Sea pipeline.