The UK’s statistics watchdog on Thursday said that it is “looking into” the government’s recent announcement that it had met Prime Minister Rishi Sunak’s target to clear the country’s asylum backlog by the end of 2023, a claim strongly contested by the Opposition.

Earlier this week, the UK Home Office said that 112,000 asylum cases were processed in the past year, which exceeded Sunak’s initial target of 92,000 applications pending at the end of 2022.

However, the Opposition Labour Party had contested this and accused the government of “misleading” the public. It has now emerged that a formal complaint is likely to have been raised with the Office for Statistics Regulation (OSR), which independently monitors the use of official statistics.

“The Office for Statistics Regulation confirmed it is looking into the government announcement about the asylum backlog,” said a spokesperson for OSR.

While the OSR can ask for additional information from the Home Office, it does not have the power to compel data to be provided. It can, however, withdraw the high quality “kitemark” it provides the Home Office with reference to their statistics released over the course of the year.

In a statement from Tuesday, the Home Office claimed that fundamental changes to the decision-making process and boosting efficiency resulted in the highest annual number of “substantive” asylum decisions in a year since 2002. It cited the use of stepped up processing, deploying an additional 1,200 caseworkers, meeting the target to double the number of asylum caseworkers and tripling productivity to ensure more illegal migrants are returned to their country of origin quicker.

All cases in the so-called “legacy backlog” were said to have been reviewed, with 86,800 decisions made. In one four-week period from November 20 to December 17, 2023, there were 20,481 initial asylum decisions made, this is more than the number of asylum decisions made in the entirety of 2021, the Home Office statement said.

Around 4,537 claims from the so-called legacy backlog still needed a decision but Sunak’s spokesperson at 10 Downing Street said that since these had been reviewed, the government considers them as “cleared”.

The government describes these as complex cases, typically involving “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”.

“I said that this government would clear the backlog of asylum decisions by the end of 2023. That’s exactly what we’ve done,” Sunak said on Tuesday.

However, Labour responded to say that the government’s claims are “just not true”.

“Sunak claims to have cleared the asylum backlog. Not true. Not even cleared ‘legacy backlog’ – 4,500 cases not done, 17,000 ‘withdrawn’ by the Home Office but they’ve no idea where those people are, and rest of backlog doubled this year,” said shadow home secretary Yvette Cooper in a post on social media.