Rishi Sunak has previously pledged to “abolish” outstanding asylum applications by the end of 2023, with the Home Office charged with dealing with “legacy claims” made before June 2022.

James Cleverly yesterday insisted that the Government had met this target, while a tweet from Mr Sunak suggested that officials had cleared the entirety of the backlog of claims.

However, the latest official figures showed that more than 4,500 of these legacy cases were yet to receive an official decision as of the end of December.

In addition, over 90,000 applications made after June 2022 are still in the system.

Mr Cleverly yesterday insisted that the Government has “done what we promised” to deal with the cases.

The Home Secretary told BBC Radio 4’s Today programme that the commitment was to “make sure we process” the 92,000 legacy claims, and that the cases that had not received a decision were among those which had been processed.

“Every single one of those applications has been processed,” said Mr Cleverly.

“In the vast majority, a final adjudication has been made.

“In a small number – about 4,500 where there are discrepancies, where there are further checks, additional work needs to be done.”

The Home Office has said the 4,500 complex cases typically involve “asylum seekers presenting as children – where age verification is taking place; those with serious medical issues; or those with suspected past convictions, where checks may reveal criminality that would bar asylum”.

Labour, and the think tank Migration Watch UK, meanwhile questioned what had happened to migrants whose claims had been refused.

Alp Mehmet, the chairman of Migration Watch UK, said: “The Government is playing fast and loose with the figures. The public will not be fooled by smoke and mirrors.

“The Home Office may have moved a few papers from the pending to the out-tray by giving thousands the benefit of the doubt but they have not done anything to dissuade other migrants from getting to the UK by whatever means they can, including in a small boat.”

Yvette Cooper, the shadow home secretary, also said the Government’s claim were “not true”, while her deputy Stephen Kinnock described the Prime Minister’s claim as a “barefaced lie”.

The Home Secretary yesterday dismissed claims that the drop in small boat arrivals was due to factors such as the weather, rather than Government policy such as its non-functional Rwanda scheme.

Speaking to BBC Breakfast, Mr Cleverly said: “This is nothing to do with the weather, I know this is a convenient way of overlooking the incredibly hard work our officials have done with their colleagues across Europe. This is not about the weather.

“In fact, the number of good sailing days this year was only four fewer than the previous year. There were 102 good sailing days this year, 106 sailing days last year, so the weather is not a contributory factor.

“The 36 per cent reduction is because of a number of things including co-operation with our European partners, including France, including Albania, including Romania, Germany and others.”

Mr Cleverly told LBC on Tuesday that “my target is to reduce it to zero, to stop the boats” in 2024, but this was not repeated by Downing Street.

The Rwanda Bill is expected to be brought to Parliament in the next two weeks.

Asked whether the Channel crossings could be stopped in 2024, the spokesman replied: “We need to ensure Parliament has its say. I’m not going to set out a deadline. We want to do this as soon as possible, that is why we are introducing this Bill, which we believe that Parliament will support because it is what the public want to see.”

Government accused of lying over asylum backlog claims