There is a 'very high risk of a terrorist attack' against Western allied evacuation operations in Afghanistan, according to a senior British source.
The security of evacuation operations is already extremely precarious as the UK, US and other allied forces have had to rely on the Taliban to allow evacuees into the airport as their fighters now control the surrounding areas.
The unnamed source told Sky News that an affiliate of the ISIS, the Islamic State Khorasan (ISIS-K), is among the most dangerous of threats to evacuation operations with a history of car and suicide bombings.
Government ministers have raised concerns that ISIS-K could launch a terror attack on allied troops and civilians amid the sea of people at the bottleneck of the airport gates.
The Taliban announced this morning they would begin to block civilians reaching the airport, defying US President Biden's demands of allowing access to the airport 'for those who are transporting out and no disruptions to our operations'.
This, coupled with the August 31 final withdrawal deadline issued by Taliban leaders, means civilian mercy flights will have to stop in the coming hours so that planes can be diverted to evacuate troops.
Biden has committed the US to withdraw by August 31, a decision that western allies warn will mean thousands of Afghans who were promised sanctuary being left behind
President Biden on Tuesday said the US is on pace to finish evacuations from Afghanistan on time, but an August 31 withdrawal would leave thousands of desperate civilians behind
Allied forces are assisting with of people crowded outside the airport in Kabul, but ministers fear an ISIS affiliate could launch a terror attack amid the pandemonium
Tory MP Bob Seely branded the manner of the West's departure from Afghanistan a 'categoric disaster'.
He warned that the idea al-Qaida militants would now take up 'basket weaving in the Hindu Kush' rather than plotting terror attacks was 'for the birds'.
'If this does destroy Biden's presidency, you have to question his fitness for the role,' the MP told MailOnline.
'You have got to question Trump's moral fitness for the role, but you have got to address Biden's intellectual fitness and health fitness for the role.
'I'm sorry, he is just gaga… he doesn't have a grip. How many slip ups before people think yep, he can't do the job.'
Former chief of UK defence staff Lord David Richards said British flights will have to stop by Friday. France has said it will stop flights tomorrow, Poland has already stopped flights, and Hungary has signaled that its mission is also drawing to a close.
British foreign secretary Dominic Raab admitted this morning that the mercy missions are now into their final hours with some 4,000 people - 1,250 western citizens and 2,500 Afghans - still left to rescue, though he did not say exactly when the final flight will leave or how many people may be left behind.
That has sparked renewed desperation at the airport, as hundreds of Afghans wanting to get on the planes have taken to wading across an open sewer underneath walls where western troops stand guard - waving papers in the hopes of being picked up.
Fears are now growing that civilians could rush the runway and trigger a deadly stampede in a repeat of the horror scenes from last week, or else opportunistic terror groups such as ISIS could attack packed crowds.
Fears are growing that crowds could try to storm the airport once civilian mercy flights stop, or that opportunistic terrorists could attack the densely-packed crowd
Desperate Afghans waded through a sewage ditch on the outskirts of Kabul airport this morning while pleading with soldiers guarding the opposite bank to put them on a plane out of the country as time runs out to flee Taliban rule
A US marine comforts a child at Kabul airport as the evacuation operation nears it end, with US allies saying flights could stop within the next 24 hours
Mr Raab was also forced to admit that the coming days will present 'maximum danger' for British troops, fearing both a 'Saigon' moment with crowds rushing planes and threats of a 'spectacular' terrorist attack.
But, Mr Raab insisted, Britain will keep flying planes out of the country until the last possible moment in the hopes of getting as many people out as possible.
One British soldier, speaking anonymously to the Daily Telegraph, said his 'biggest fear' is a stampede at the airport and that 'the civilians might try and get in any way they can and potentially put us all at risk.'
'Unfortunately the quantity of civilians arriving is something we cannot control, with the majority of them not being eligible to be evacuated,' he said, adding: 'I and many others have seen a few mentally disturbing scenes. I think there will be more of that.'
Exactly how and when allied forces will leave the airport entirely is being kept a closely-guarded secret, amid fears that the news of a full exit could spark a rush of desperate people at the gates.
Underlining the risks, one defence source told The Telegraph: 'It could be the airfield gets compromised by a massive incursion. It could be that the Taliban have an element that wants to put up a fight in the last days. It could be that ISIS wants to do a 'spectacular'.
The Pentagon said on Wednesday that US forces have 'been very clear' with the Taliban 'about what credentials we are willing to accept' for people trying to get to the airport.
'By and large, with caveats' people have been getting through checkpoints, spokesman John Kirby said, adding 'we also have other means to get people in.'
'When we have reports that someone credentialed is not being let in, we are making that clear to Taliban leaders they need to let them in,' Kirby said.
It was also revealed that a military operation recovered 'less than 20 people' from Kabul under cover of darkness and brought them safely to the airport for evacuation.
Members of the GOP said on Tuesday night that Biden has 'blood on his hands' because thousands of American citizens and Afghan allies who helped U.S. troops could be left to die when the final evacuation flights depart - which could even be before midnight on Aug. 31 to ensure a safe evacuation of everyone at the airport.
Rep. Seth Moulton, a Democrat from Massachusetts, and Rep. Peter Meijer, a Republican from Michigan, who underwent a secret trip to Kabul to witness the situation at the airport for themselves, challenged President Biden and claimed that 'we won't get everyone out on time'.
Raab was forced to admit that the coming days will present 'maximum danger' for British troops, but insisted that Britain will keep flying planes out of the country until the last possible moment
How Biden has backed himself and his allies into a corner and now has little choice but to follow the Taliban's lead
Surrounded on all sides by the Taliban, babysitting a humanitarian crisis, and reliant on a single runway as an escape route - this is the situation faced by thousands of western troops at Kabul airport.
Though Joe Biden likes to give off the impression that he is still calling the shots in Afghanistan - warning the Taliban yesterday that evacuation flights must be allowed to proceed unimpeded - in reality he has 6,000 men and women in harm's way, and he knows it.
With all other US forces already out of the country, the troops at Hamid Karzai Airport are badly isolated and - as UK defence secretary Ben Wallace pointed out on Tuesday - all the Taliban need to do to cut them off further is to land a few mortars on the runway.
Biden tacitly acknowledged the situation on Tuesday when he told Americans that 'the sooner we can finish , the better,' adding that 'each day of operations brings added risk to our troops.'
In short, western forces are woefully unprepared for any sort of confrontation with the Taliban - meaning Biden has little option but to sing to the Islamists' tune.
Perhaps the starkest example of the new power dynamic was the Taliban's announcement last night that it will now block Afghans from reaching the airport - a statement that was issued at almost the same time Biden demanded that people be allowed through.
It came as little surprise to learn that Taliban fighters were paying no attention to Biden today - beating one Australian man bloody as he headed to the airstrip while turning others back.
The only way to stop them, according to former head of the British armed forces General Sir Richard Barrons, would be 'to leave the airport, and fight the Taliban to go and get these people.'
'I just don't see that as a credible proposition,' he added.
As Ben Barry of the International Institute for Strategic Studies put it to The Telegraph: 'The UK and the US need to recognise that the country is under new management.
'The Taliban won… They are the landlord and the last thing you want to do is upset the landlord.'
