Thousands of asylum cases that Rishi Sunak claimed had been cleared are on course to be returned to the Home Office because of soaring appeals blamed on “rushed” decisions and processing errors. Legal challenges were lodged against more than 29,000 decisions in 2022-23, almost four times the figure seen the previous year, causing a new backlog to build in the specialist court charged with hearing the cases. A Home Office official said that civil servants are now having to reconsider claims “from scratch” that were refused and withdrawn in the push to meet the prime minister’s pledge to process a backlog of more than 90,000 older asylum claims by the end of 2023. “Processing changes were implemented from last July onwards so that we could clear the backlog but the legal risk was high,” they added. “Many cases will go straight back into the backlog.” On 2 January, Sunak said in a statement: “I said that this government would clear the backlog of asylum decisions by the end of 2023. That’s exactly what we’ve done.” While half the “legacy” asylum claims decided last year were granted, 28% were refused and a further 22% were withdrawn by the Home Office, mostly without applicants’ consent. Among the asylum seekers fighting the decisions is a disabled Iranian man who is deaf, mute and visually impaired, and was refused asylum after the Home Office decided not to conduct an interview. In a separate case, an Egyptian man won an appeal after the first-tier tribunal found officials had wrongly rejected his case and ignored supporting documents because “the translations did not come from a UK translation agency”. While a judge found the man to be “consistent” and backed by “impressive witnesses”, the Home Office had rejected his account of persecution and accused him of providing “insufficient detail”. Documents seen by the Observer show that the Home Office has also reversed some of its own decisions after internal reviews and before scheduled court hearings. “It has been concluded the decision to refuse is no longer appropriate and the immigration decision is therefore withdrawn,” said a letter sent in January. “It is anticipated refugee status will be granted.” An official report released by the Ministry of Justice said a 330% year-on-year rise in asylum appeals in the most recent quarter “stemmed from the Home Office tackling its legacy asylum decision backlog”. More than half of appeals to the first-tier tribunal were granted in the year to March and if the success rate continues, at least 14,000 cases could add to a backlog already running at more than 83,000. Labour has said it will fully process all outstanding asylum claims if it wins the general election and recruit more than 1,000 Home Office caseworkers to clear the backlog while speeding up removals of refused asylum seekers. A party source said leaders were aware that they would be “inheriting an absolute mess of botched legislation, a huge backlog of cases and a growing appeals backlog”. Decisions quashed by judges must currently be remade by a specialist secondary casework team at the Home Office, which may have to conduct new interviews and request further documents. “It’s a laborious process because you have to check what the judge thought of the case, what didn’t get asked – or not well enough – and collect that information,” the Home Office official said. They said a two-hour limit imposed on asylum interviews last summer meant civil servants “ended up running out of time and being unable to collect enough detail”, leaving the resulting decisions open to legal challenges. The issue was compounded by the introduction of “concise” templates for explaining refusals, which prevented officials from fully outlining their reasoning, the official added. Further appeals are expected to be lodged because of a time lag caused by a shortage of publicly funded solicitors to represent affected asylum seekers. A Home Office spokesperson said its processes were underpinned by a robust framework of safeguards and quality checks and insisted claims were properly considered. A statement added: “We have taken action to speed up asylum processing while maintaining the integrity of the system. With more claims being processed, it stands to reason that more appeals will be submitted.”