A "senseless" benefits test is costing the NHS almost £8 million a year as a result of extra GP appointments or attendance at A&E, a charity has claimed.
The MS Society, which supports people with multiple sclerosis, hit out at a rule which can stop people able to walk more than 20 metres from claiming the higher rate of mobility support under the personal independence payment (PIP).
The charity, which is calling for the 20-metre rule to be scrapped, said under the previous benefit - disability living allowance (DLA), which had a 50-metre test - 94% of claimants with MS qualified for the higher rate of support, but just 66% do under PIP.
As a knock-on effect, MS sufferers were forced to make increased use of NHS services, the charity said.
MS Society director of external affairs Genevieve Edwards said: "Contrary to the Government's insistence that PIP is meant to help those with the greatest needs, the truth is it's causing enormous harm to people with MS, with many losing their independence as a result.
"This senseless and unfounded rule is leading to people with the highest need facing the biggest losses, and costing our NHS at least an extra £7.7 million each year."
A survey of 1,234 people with MS was carried out by ICM Unlimited between January and March 2018, including 447 people who moved from DLA to PIP.
Of those, some 39% said they had increased their use of GP services since the change and 30% claimed they had been forced to cut back on spending on treatment or therapies.
Waqar Rashid, a consultant neurologist at Royal Surrey County Hospital University Foundation NHS Trust, said: "There's no scientific rationale or basis for the recent change to the 20-metre rule and it's impacting services as well as people with MS.
"I see people become isolated and depressed, and then contact GPs with more related issues.
"I've even seen patients asking MS therapy centres to provide additional services that PIP would have paid for. They're picking up the pieces and frankly it doesn't make sense."
A Department for Work and Pensions spokesman said: "We introduced PIP to replace the outdated DLA system.
"PIP is a fairer benefit, which takes a much wider look at the way an individual's health condition or disability impacts them on a daily basis. A higher proportion of people with MS receive the highest possible award under PIP than under DLA.
"We work closely with organisations such as the MS Society to ensure that PIP is working in the best way possible, and we recently announced that people with the most severe, life-long conditions will no longer have to attend regular reviews for PIP."
Copyright (c) Press Association Ltd. 2018, All Rights Reserved. Picture (c) MS Society.