Kate Rae, from Aveley, Thurrock, in Essex, was keen to get back to work after being diagnosed with a serious disability. And for four years, government support, in the form of the disability living allowance, allowed her to do so.

But in January, six days into a new job as an events sales executive for a four-star London hotel, Rae got a letter saying that her reassessment for the new personal independence payment (PIP) had found her capable of walking between 20 to 50 metres. She no longer qualified for a Motability car, crucial for her journey into London for work. Without it, she was forced to give up her job.

This weekend, Rae, 40, was dealt another blow: she expects to be one of the 200,000 disabled people who will lose benefit altogether, according to a Labour analysis, under further changes to disability benefit to be included in Wednesday’s budget.

“It is the last straw for me,” said Rae, who has chronic pain and Ehlers-Danlos syndrome, a disorder causing poor balance that makes walking difficult. “Under the new scheme, I will no longer qualify. I don’t know what I’m going to do. How am I supposed to feed myself, clothe myself? Without these things, I can’t get ready to work.”

Under the old scheme, Rae would have been awarded eight points, for help with daily living, including two for an aid to help with dressing and undressing and two for an aid, such as a rail support, for going to the toilet, giving her £56 a week in daily care allowance. If she was reassessed under the new criteria, she would only score six points, which means no award.

This week, after much soul-searching, she is packing up her house to move to Shropshire so that “my mum can look after me”.

“I’ve lived independently all my life since I was 18,” said Rae. “I’ve been working since I was 14. I had seven years out of work when I first was disabled, but, through work, I was starting to feel like a proper person. They’ve taken away my ability to do that. Now I’m back to feeling like a poor little disabled girl again.

“We’re being treated like a financial inconvenience. The government forget that there are actual lives at the end of these changes.”

Disabled charities have described the plans, which is expected to hit an additional 400,000 people who will see their weekly PIP payments fall from an enhanced £82 to the standard £55, as devastating. They say cuts to benefits helping people to lead independent lives is a “false economy”.

The cuts are the latest in a string of reforms, including the change from disability living allowance to PIP, to proposed changes to employment support allowance and the cuts to social care that have affected disabled people.

Bethen Thorpe, an actor and former pub landlady from Highgate, north London, also expects to be among the 200,000 people who face having their benefit stopped under the measures in Wednesday’s budget.

Thorpe, who was diagnosed with multiple sclerosis in September 2014, after losing the use of her left side and suffering vision problems, accused the government of discrimination.

“With the cuts to employment support allowance and the proposed cuts to PIP, I do feel discriminated against,” said Thorpe, 39. “These cuts are against some of society’s most vulnerable people, with the proviso that they won’t fight it.”

Following her diagnosis two years ago, Thorpe applied for PIP and was refused, but successfully appealed against the decision. Her appeal awarded her nine points, for standard daily living, including two points for an aid for using the toilet and two for an aid dressing and undressing. Under the proposed rules for each of these tasks, she would only receive one point, bringing her total to seven points and no award.

“If I don’t qualify, I will have no money coming in,” said Thorpe. “It is counterproductive to what they are saying disabled people should be doing. PIP can help cushion you getting into work or help you travel there. Without it, people with disabilities are less likely to get back to their normal lives.”

Disabled people and their relatives contacted the Guardian in response to an appeal for stories of experiences with the changes. One woman, from Nottingham, said she feared her mother, who has osteoarthritis as the result of a car accident, would lose her benefits.

The woman, who did not want to be named, said: “I’m incredibly angry. This will have a knock-on effect. My mum worked for 40 years, most recently as a housing officer. She helps me out with my son and she helps out her former husband, who has mental health problems. She is going to be trapped in her bungalow. They are targeting the wrong people.”

Liz Sayce, chief executive of Disability Rights UK, said: “It’s a false economy to make cuts in the very areas that enable people to get their lives on track. We profoundly believe that disabled people have got so much to contribute to British society. But with the cuts to benefits, social care cuts and now the tighter regulation to PIP, we are really concerned it will jeopardise independent living for disabled people, leaving them socially isolated.”

A spokeswoman from the Department of Work and Pensions said: “The truth is that these changes are about ensuring that PIP is achieving its original purpose of supporting people with the extra costs associated with their disability. We have consulted widely with disability organisations, to ensure we get this right, and have been careful to protect people with the most complex needs. We continue to spend £50bn a year on disability benefits.”

She said the majority of people leaving the motobility scheme would be eligible for a £2,000 one-off payment and that claimants could also apply for an access to work grant for support to get to work.

Analysis by DWP found that 33% of claimants who receive the daily living component of PIP qualify solely due to their use of aids and appliances.