The Department for Work and Pensions has been pulled up by the ombudsman for failing to compensate benefit claimants whose payments were cut by mistake.
Around 118,000 people with disabilities and health conditions had their benefits wrongly reduced when moving to Employment and Support Allowance (ESA) around a decade ago.
It was all linked to an internal DWP error that resulted in claimants being underpaid.
While the DWP has since corrected the error and handed out backpay totalling £613million to those affected – the Parliamentary and Health Service Ombudsman (PHSO) said people should have been compensated too.
Those affected are "facing injustice" and should be able to claim compensation in recognition of the error and its "potentially devastating impact" on their lives, the ombudsman said.
It follows an investigation by the ombudsman into the case of one claimant, known as Ms U.
The 62-year-old missed out on vital support because of the error and was thrown into "extreme financial and personal hardship".
Her payments were wrongly cut by around £80 a week for five years when she was transferred onto ESA in 2012 - leaving her unable to heat her home and afford food.
She only received payments based on her national insurance contributions, but should also have received payments based on her income.
The lower payments also meant she lost access to financial help such as free prescriptions and the warm home discount worth £700 over the years.
She was given £19,832.55 in backpay by the DWP after the error was identified.
Have you received back pay for this error? Get in touch: mirror.money.saving@mirror.co.uk
But the ombudsman ordered the DWP to also apologise and pay £7,500 in compensation because of the "maladministration".
Now the ombudsman says the government should consider payouts for all of those affected because of the "potentially devastating impact" the error had on people's lives.
Ombudsman adjudicator Rob Behrens said: "It is human to make mistakes but not acting to right wrongs is a matter of policy choice.
"In this case, that choice has been made by the very organisation that is responsible for supporting those most in need.
"We don't know how many more Ms Us there are out there. That is why I urge the DWP to allow people affected to claim for compensation in recognition of its error and the potentially devastating impact it has had on people's lives."
A DWP spokesman said: "Our priority is that all people get the financial support to which they are entitled and we have identified those affected by this issue, making 118,000 benefit arrears payments in full."
I was underpaid, could I get compensation?
The government has not agreed to pay compensation to everyone who was wrongly underpaid, however, anyone that was severely affected has the right to make a complaint to the DWP.
The more evidence you have of your hardship the stronger your case will be - so if you missed out on vital support or were forced into debt, you could get money back to cover those payments.
If you’re unhappy with the DWP's outcome, you can ask your local MP to escalate your case to the PHSO.
This is an independent body which deals with complaints left unresolved by the NHS or the Government.
The PHSO says that anyone affected should contact their welfare rights service at their local council or Citizens Advice.
Louise Rubin, head of policy at disability equality charity Scope, said: "This catastrophic error will have left many disabled people and their families struggling to make ends meet.
"Disabled people shouldn't have to fight for support. It's only right that the Government now ensures all those who missed out can claim compensation."
Claimants can contact the DWP on 0800 169 0346 for more information.
The average payout from underpaid ESA in arrears is £5,000.
But some on a severe disability premium could be owed £11,500 each and a “small number” could get around £20,000.
