A compensation scheme for people whose lives were devastated by the Windrush scandal has been criticised for being slow and inefficient, as the latest figures show hundreds of cases have been in the system for at least a year.

A lawyer who has met hundreds of people needing help with their claims has accused the Home Office of institutional racism, saying she believed no other group of people in society would be treated “this callously”.

Jacqueline McKenzie, partner at the law firm Leigh Day, said they had had clients who were initially rejected for any compensation who were then offered tens of thousands when their case was reviewed in what she said is evidence of “poor case-working”.

The Windrush Compensation Scheme is available to people of all ages and nationalities including those from African, Asian and Caribbean backgrounds who have suffered due to being unable to prove their legal right to live in the UK.

It was set up after the Windrush scandal, which erupted in 2018, saw people with a right to live in the UK lose access to work and be wrongfully detained or deported.

The latest figures show that, since 2019 and up to April this year, £72.6 million had been offered through the scheme – of which £61.3 million had been paid out.

PA analysis shows that of the 2,235 claims in progress as of April, 347 (16%) had been in the system for at least 12 months, including 162 for over 18 months.

A year earlier in April 2022, a lower number of claims were in progress – 1,904 – but a higher number had been in the system for 12 months and over: 541, or 28% of the total.

Over the same period, the proportion of claims in the system for just one to three months has gone up, from 19% in April 2022 to 33% in April this year.

Ms McKenzie said the “system is so slow” – and her comments came as a leading campaigner told of his fears the Home Office could be working towards closing the scheme.

Patrick Vernon’s concerns come in the 75th anniversary week as it was reported that the Home Office unit set up with responsibility for reforming the department in the wake of the scandal – which saw many lose homes, jobs and face the threat of deportation – is to be disbanded.

The Home Office has said the Government is “honouring its Windrush commitments and providing support to those affected every day”, adding that the compensation scheme “will stay open as long as needed”.

On the scheme, Ms McKenzie said: “It takes about 12 months to get an initial decision. And then those initial decisions are often wrong.”

She said the firm had a client who put an application in and was told he was not entitled to any compensation, but when it was reviewed he was told he is entitled to £289,000, while another saw a mother and two daughters go from zero to being told they are entitled to between £70,000 and £100,000.

Asked why she thinks they are seeing such drastic changes when cases are reviewed from initial rejections, she said: “I think some of the problems are that they’ve not resourced the team.

“They themselves say they’re under-resourced so that’s a big issue but also very poor quality case-working.

“I think they’re inefficient. I just don’t think that the Home Office has properly skilled this up.”

She said her team have been involved in tier one reviews of cases and they have felt due diligence was not done on the cases initially.

“The case was there, there was enough evidence there,” she said.

“Even if people haven’t put in all the legal language, the Home Office can see from those cases that this is somebody who’s eligible, why don’t they just phone them up and say ‘well, we need a bit more of this’, or send a letter and say ‘well, we need that’.

“They don’t do that and it’s so distressing because remember, these people are seriously traumatised. I have not met anybody affected by the Windrush scandal that’s not traumatised.”

The 2020 Lessons Learned review into the scandal found the Home Office had demonstrated “institutional ignorance and thoughtlessness” towards the issue of race and the history of the Windrush generation.

But its author Wendy Williams said the actions did not satisfy all of the features of institutional racism.

Three years on, Ms McKenzie said she believes “you can’t have tenets of racism without racism, you can’t be a bit racist – you’re racist or you’re not”.

If you’re not seeing how you’ve damaged and traumatised a group, if you can’t see that that (the scheme) is a priority, to me it’s that you’re seeing them as less than and that is institutional racism

She said: “I think it’s difficult to find any other explanation for me. Unless you’ve just got a whole load of inefficient people and I don’t think they are. And I think there are people in the Home Office who really care.

“I think it’s a mixture of inefficiency, lack of prioritisation and institutional racism. I don’t believe they would treat another group in society this callously.

“There are advocates, there are people speaking up. The media is constantly over this story and yet we’re still where we are five years on. How is that possible?

“It must mean that you’re not seeing it as a priority. If you’re not seeing how you’ve damaged and traumatised a group, if you can’t see that that (the scheme) is a priority, to me it’s that you’re seeing them as less than and that is institutional racism.”

A Home Office spokesperson said the department remains “absolutely committed to righting the wrongs of Windrush” adding that they are “determined to create a Home Office worthy of every community it serves”.

They added: “Through this work, we will make sure that similar injustices can never be repeated.”