Dominic Raab faces a grilling over what has been described as “the biggest failure of foreign policy in a generation” on Wednesday, as the government announced that some evacuees from Afghanistan would be given indefinite leave to remain. Accusing Raab of multiple failings, the shadow foreign secretary, Lisa Nandy, urged him to explain how the government had been left scrambling to airlift thousands of people after the Taliban swept into Kabul. “The foreign secretary had 18 months to prepare but was missing in action. As a result, on his watch Britain has become weaker in the world and faces greater risks from terrorism,” Nandy said. Raab has faced mounting criticism over his decision to go ahead with a holiday in Crete in August and claims that thousands of emails from people seeking help to leave Afghanistan had gone unread. The prime minister’s official spokesperson insisted Boris Johnson had “full confidence” in Raab and there were “no plans” for a reshuffle – but there is widespread speculation he could be moved. Ministers will announce on Wednesday that refugees arriving under the Afghan relocation and assistance policy (Arap), designed for interpreters and others who supported Britain in Afghanistan, would immediately be granted indefinite leave to remain in the UK as part of “operation warm welcome”, allowing them to study and work. Michael Gove, the chancellor of the duchy of Lancaster, is expected to be put in charge of a committee overseeing the scheme, according to leaked details of a briefing to MPs by the defence secretary, Ben Wallace. MPs on the cross-party foreign affairs committee have been given an hour to question Raab on Wednesday about what one member, Labour MP Neil Coyle, called, “the worst crisis since Suez”. The committee chair, Tom Tugendhat, expressed his dismay at events in Afghanistan on Tuesday, tweeting: “Ending wars is good. Leaving people defenceless in front of armed gangs is not how you end a war, it’s how you start a new one.” Raab gave a foretaste of how he is likely to respond to MPs’ questions in a series of difficult media interviews, in which he rounded on what he called “backbiting finger-pointing peripheral people involved in buck-passing”. He also denied the UK had been slow to foresee the crisis, saying the central estimate of military Nato intelligence was that there would be a slow incremental progress by the Taliban after August. Nandy said he should be pressed about the government’s apparent complacency in the run-up to the US withdrawal, with the prime minister telling MPs in July there was “no military path to victory for the Taliban”. As well as challenging him about the chaotic events of recent days, some committee members hope to question Raab about what the Afghan crisis means for wider foreign policy. Isle of Wight MP Bob Seely said the departure of western troops after two decades could embolden Moscow. “It is quite clear that if the Russians see Nato as being a busted flush, or very vulnerable … the Russians will try to break Nato, and to partition Ukraine and destroy Ukraine as a state,” he said. Claudia Webbe, the MP for Leicester East, said she planned to raise Raab’s possible resignation because of a series of failings by his office and his department. “Under his watch there appears to be a lack of joined-up work and intelligence regarding the situation in Afghanistan. No discussions were held with neighbouring countries about the extent of the security threat and thus no plans put in place for a ‘what if’ scenario,” she said. Graham Stringer, a Labour member of the committee and the MP for Blackley and Broughton, said Raab’s decision to remain on holiday as Kabul fell to the Taliban was “not a good look” but would not necessarily lead to him being forced from office. But he said: “The big, outstanding issues for me are how the government reacted after the Trump and Biden decisions [to quit Afghanistan]. And whether the country in future should negotiate the basis or our relationship before we get into bed with a superpower.” Stringer said Tony Blair’s government must accept much of the blame for failing to discuss an exit strategy when the UK entered the conflict. “We should have gone in, destroyed the al-Qaida bases, either captured or killed [Osama] Bin Laden and got out within months. Blair got into bed with [George W] Bush and everything followed. It was a disaster of international policy – both Afghanistan and Iraq,” he said.