LONDON — Britain’s Labour Party government on Tuesday announced an overhaul of the welfare system that it says will save the cash-strapped administration 5 billion pounds ($6.5 billion). Critics claim it will harm some of the U.K.’s most vulnerable people.

The government says the shakeup will help people who are currently “written off” find jobs. It’s a risky strategy for a party founded more than a century ago to fight for the rights of working people, and it has made trade unions and party supporters uneasy.

Work and Pensions Secretary Liz Kendall told lawmakers in the House of Commons that the government had inherited a broken social security system that is “failing the very people it is supposed to help and holding our country back.”

She said Britain’s statistics are stark, with one in 10 working-age people claiming a sickness or disability benefit, and “millions of people who could work trapped on benefits.”

Blaming the Conservatives, who lost power in July after 14 years, for damaging the economy and health system, Kendall said “the social security system will always be there for people in genuine need.”

But she announced changes to the way disabilities are assessed. Campaigners say that will make it harder for people to get and keep benefits.

The changes, which will have to be approved by Parliament, are expected to save more than 5 billion pounds by 2030.

Not everything is being cut. The overhaul also includes an above-inflation increase to universal credit, one of the most common welfare benefits. Kendall said 1 billion pounds will be spent to “tear down barriers to work,” including new rules allowing welfare recipients to try out paid jobs without losing their benefits.

The government claims a lack of support towards employment is trapping sick and disabled people in economic inactivity. Kendall said that “in most comparable countries” spending on sickness and disability benefits “is either stable or falling – whilst ours continues to inexorably rise.”

The Disability Benefits Consortium, which represents more than 100 charities and organizations, said the “cruel” changes “will largely hit those who are unable to work and rely on these benefits to survive.”

Sarah Hughes, chief executive of mental health charity Mind, said the cuts would make it harder for people to get support and “will only serve to deepen the nation’s mental health crisis.”

Prime Minister Keir Starmer ’s center-left government has seen its popularity plummet as it grapples with a sluggish economy and creaking public services.

Treasury chief Rachel Reeves is due to make a spring budget statement on March 26, and is expected to trim public spending to make up for lower-than-expected tax takings and high borrowing costs.

Tuesday’s welfare announcement followed weeks of speculation about how deep the cuts would be.

Labour lawmaker Imran Hussain said that “thousands of the most severely disabled people in my constituency, and millions across the U.K., have watched in disbelief as politicians debate cuts to the support that enables their very survival, leaving many at breaking point.”

Kendall said she understood “the worry and anxiety.”

“And I hope I’ve made it clear to the House today, I don’t start from a position of being tough,” she said. “I start by precisely from a position of compassion.”