About 7,000 long-term sick people across the former Avon area face a £25-a-week benefit cut, under harsh Tory plans unveiled this week.

The Conservatives pledged to remove incapacity benefit (IB) from the one-in-five claimants believed to be able to work, by testing all 2.6 million claimants within three years.

Anyone judged ineligible to claim IB would be placed on job seekers' allowance (JSA) – which pays £64.30 a week, instead of a typical £89.90.

With a fifth expected to fail the tougher test, and 38,000 IB claimants across the former Avon area, the crackdown would hit about 7,000 people in the region.

Last night, the Conservatives said the shake-up would save £600m over three years, sufficient to fund the party's new Work Programme to speed up help for the jobless.

Mr Cameron said: "Labour has never really bitten the bullet of proper welfare reform. Instead of just pilot schemes for people on incapacity benefit, we are going to go through the 2.6m people.

"Everybody knows some of those people cannot work and must be helped – we are a compassionate society and must look after those people – but some of those people can work."

The £600m savings would fund help for the young jobless after six months of unemployment.