Suella Braverman has rejected calls to move responsibility for the Windrush compensation scheme from the Home Office, saying it would cause “delay and needless bureaucracy”.

The scheme, set up in the wake of a scandal which saw many British citizens wrongly detained or deported, has been criticised as being complex while the process of handling claims and offering payouts has been branded slow and inefficient.

But the Home Secretary said changes had been made to simplify the scheme for users, and maintained it should be kept under the Home Office remit.

In an interview with ITV News as Britain prepares to mark the Windrush 75th anniversary, she said: “It’s right that the Home Office maintain ownership over the scheme because to do otherwise would cause delay and needless bureaucracy.”

Campaigners and a lawyer who has helped claimants over the years have argued that people do not have faith in the Home Office, and said it is inappropriate to have the “perpetrators” of the scandal running the compensation scheme.

Meanwhile, Age UK has said the scheme is letting down older people with “increasing numbers dying before ever receiving the compensation they are due”.

The latest Government figures for May show hundreds of people have been in the system awaiting a claim outcome for at least a year.

As of last month, £75.0 million had been offered, with £62.7 million of that paid out.

The Home Office has said it remains “absolutely committed to righting the wrongs of the Windrush scandal” but recognised there is “more to do” when it comes to the compensation scheme.

Analysis by the PA news agency of the most up-to-date figures published on Wednesday shows that of the 2,138 claims in progress as of May, 302 (14%) had been in the system for at least 12 months, including 154 for more than 18 months.

A year earlier in May 2022, a lower number of claims were in progress – 1,953 – but a higher number had been in the system for 12 months and over: 592, or 30% of the total.

Over the same period, the proportion of claims in the system for just one to three months has gone up, from 20% in May 2022 to 32% in May this year.

The May 2023 figures are an improvement on April, when 347 (16%) of claims had been in the system for at least 12 months, including 162 for more than 18 months.

Thursday will see celebrations held across Britain to mark the 75th anniversary, including a commemorative service at London’s Southwark Cathedral, and the Windrush flag being raised in locations including the Houses of Parliament and the Home Office.

Windrush campaigner Patrick Vernon has voiced his concerns that the compensation scheme will be wound up entirely in the next year, and called on the Government to give a “categorical no” to that happening.

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”.

This week it was reported that the Home Office unit set up with responsibility for reforming the department in the wake of the scandal is to be disbanded.

The Government has also faced criticism for dropping three of the 30 recommendations made in the Wendy Williams review of its handling of the scandal – namely the establishment of a migrants’ commissioner; a call to increase powers of the independent chief inspector of borders and immigration and to hold reconciliation events.

Ms Braverman defended the department, telling ITV: “We are exposing ourselves to heightened and incredibly rigorous levels of scrutiny. We have an independent examiner of complaints, a body that’s been recently instituted, which is there to examine and provide checks and balances on our system.

“We have an independent adviser and there is a route of appeal to an independent adjudicator for those going through the process.”

Caroline Abrahams, director at Age UK, said: “The scheme’s performance is itself a scandal, with increasing numbers of older people dying before ever receiving the compensation they are due.

“Because of their ages the Windrush generation does not have time on their side so it is all the more important that the administrative process is quick and efficient.”