Hundreds of thousands of seriously ill and disabled people will become “invisible” and cut adrift from local support services as a result of the government’s £5bn programme of disability benefit cuts, experts have warned.

Claimants who do not qualify for personal independence payment (Pip) or incapacity benefits would lose a “marker of need” with local councils and NHS bodies, making it “nearly impossible” for them to access help, said the consultancy Policy in Practice.

This would “effectively erase some of the most vulnerable people” from the system – including those with life-limiting illnesses including cancer, multiple sclerosis and lung conditions – while making it harder for care services to deliver preventive support

More than 230,000 disabled people will lose access to Pip and the incapacity element of universal credit as a result of the changes, losing at least £8,100 a year, Policy in Practice estimates in a briefing. Nearly 600,000 more who do not claim universal credit will lose or not qualify in future for Pip.

On top of the direct financial hit, disabled people will struggle for visibility in local care systems that use disability benefit awards to deploy support and protection, from housing and council tax relief to debt enforcement safeguards.

Loss of disability benefits means they will lose priority status on council housing waiting lists and will be deprived of priority status in homelessness assessments, leaving them at “greater risk of prolonged homelessness”, the briefing says.

The invisibility within local care systems of seriously ill people who manage to live independently but who would be unable to access disability-benefit connected support is “one of the most troubling consequences” of the changes, it says.

“Up to now, the benefits system has always recognised and supported those too ill to work. This will change with these reforms with the unprecedented consequence of illness being unrecognised, unsupported and invisible. However, ignoring illness does not make it go away,” it adds.

It says the government is not listening carefully enough to the people whose lives will be “upended” by the measures, or consulting properly on the knock-on effects of the benefit cuts on NHS services and council social care and housing departments.

Deven Ghelani, the director of Policy in Practice, said: “For the first time ever, sick and ill claimants will be invisible within the benefits system and the cost savings [to the Treasury] are likely to be reduced as the cost of support for the most vulnerable is passed to other agencies.”

More than 3 million UK households will be hit by the changes to disability and incapacity benefits starting from next year, with some losing £10,000 annually. Official estimates forecast 250,000 people, including 50,000 children, will be pushed into poverty as a result.

The changes to Pip, announced in a green paper last month, refocus eligibility on claimants with the highest needs for daily living support. They will result in 800,000 current and future claimants losing an average of £4,500 by the end of the decade.

Ministers have insisted the changes are essential to overhaul a “broken benefits system” that denies job and skills support to ill and disabled people who can work. But they have struggled to convince MPs that the cuts are not simply crude budget savings aimed at the worst-off.

The Labour chair of the House of Commons work and pensions select committee, Debbie Abrahams, said the cuts risked creating greater ill-health among the UK’s poorest households and pushing many disabled people further from the job market.

Abrahams said the changes had triggered widespread alarm. “I met a woman while door-knocking in my constituency whose daughter has multiple sclerosis and could not cook unaided. She was worried her daughter would lose Pip. It’s creating huge anxiety,” she said.

She called on the government to pause the changes to ensure proper parliamentary scrutiny of all aspects of the green paper, including changes to Pip eligibility, which ministers insist are not up for consultation.

The Commons work and pensions committee will call Department for Work and Pensions ministers to give evidence to its disability cuts mini-inquiry, due to be held over the next few weeks. It will focus on the impact of the changes on claimant health, employment and poverty.

Abrahams, the MP for Oldham East and Saddleworth, said there was deep unease over the cuts across the parliamentary Labour party. “I wouldn’t want to use the language of revolt. But there are deep concerns. To be fair, DWP ministers are in listening mode, but this isn’t an issue that’s going away.”

A DWP spokesperson said: “We must fix our broken benefits system so it is fairer on the taxpayer, supports those who can work to find employment, and protects those who can’t.”

They added: “Our approach will always be underlined by the fundamental principle of treating people with dignity and respect, which is why we will continue to deliver a social security system for those with severe health conditions and we will protect the income of those who will never be able to work.”