Families will enjoy a two-year council tax freeze to help them cope with the credit crunch and soaring household bills, the Tories said yesterday.

Shadow Chancellor George Osborne shocked and delighted the Tory conference in Birmingham with his surprise pledge, winning a standing ovation.

Freezing the hated council tax would prove hugely popular in the South West, which has suffered bigger increases than any other region since Labour came to power.

Opposition parties denounced the measure as a "con", claiming there would have to be massive cuts in public services to pay for it.

But the eye-catching plan, which the Tories say would save the average family £210, left the Government stunned.

Mr Osborne's £1.5billion package to free hard-pressed residents from the misery of year-on-year tax hikes was his second conference bombshell in successive years.

Last year he pledged to axe inheritance tax for almost all homeowners, a move credited with forcing Prime Minister Gordon Brown not to hold a snap autumn election.

The Tories hope yesterday's unveiling of what was hailed as a sure-fire vote-winner by the delighted party faithful has the effect of halting Mr Brown's improved poll ratings since Labour's conference last week.

Since Labour came to power in 1997, the average band D council tax charge has more than doubled, from £688 to £1,374.

But people in the West have been the hardest hit, the Tories say, claiming the Government has raked in an extra £13bn of council tax in 11 years – a rise of 137 per cent.

But they say the South West has done worst, paying 168 per cent more under Labour.

South Gloucestershire had the 12th biggest rise in the country of £57,112,000, with Bristol just behind at £56,606,000.

Other areas of the West with big council tax hikes include North Somerset (up £47,724,000) and Swindon (£41,809,000), while the lowest rise, in West Somerset (up £8,308,000) was still a 111 per cent increase. Mr Osborne said a future Tory administration would allow town halls to freeze council tax by providing extra funding as long as councils keep increases to 2.5 per cent or below.

He said: "The country may not be able to afford upfront tax cuts because borrowing is too high, but families facing the squeeze cannot afford tax rises either.

"Instead of council tax bills that rise year after year under Labour, millions of families will get help at the time that they need it most. Conservatives will not leave people to struggle with the credit crunch alone. We won't walk on by. We will help families over this crisis."

The cost of the freeze would come from cuts in Government advertising and use of consultants, he said.

Some critics will see the initiative as an attack on big-spending councils, which are often Labour or Liberal Democrat-controlled, as they may struggle to keep rises down to 2.5 per cent, well below inflation.

Only 80 of more than 400 councils and fire authorities kept rises below 2.5 per cent this year, with Bristol and Bath and North East Somerset settling for four per cent, and South Gloucestershire, 4.5 per cent.

Treasury Chief Secretary Yvette Cooper said: "George Osborne's council tax pledge is a con – it could only be introduced if local councils make big cuts in public services.

"They have failed to set out where any savings would come from."

And Lib Dem spokesman Vince Cable said the Conservatives were simply "passing the buck to local councils".

He warned: "This false promise of freezing council tax will be entirely dependent on individual councils being able to cut their budgets, which is likely to leave the poorest areas with continuing council tax rises."