The UK’s evacuation mission at Kabul’s airport has “a matter of hours” left and no more people will be called forward, Defence Secretary Ben Wallace has said.

Mr Wallace told Sky News the effort was into its “final hours” after the closure of the main processing centre at the Baron Hotel near the airport.

He said: “We at 4.30 this morning, UK-time, closed the Baron Hotel, shut the processing centre and the gates were closed at Abbey Gate.

“We will process the people that we’ve brought with us, the 1,000 people approximately in the airfield now and we will seek a way to continue to find a few people in the crowds where we can, but overall the main processing is now closed and we have a matter of hours.”

“The sad fact is not every single one will get out.

“The threat is obviously going to grow the closer we get to leaving.”

The Baron Hotel was closed just hours after an attack, claimed by terror group ISIS-K, outside the airport killed 13 US troops and 78 Afghans.

Mr Wallace said he had authorised the loosening of regulations on numbers “to pack people in” on the final flights out.

He also revealed the UK closed the processing centre at the Baron Hotel “almost on time – we were always going to close it then”.

The defence secretary said the night before the attack the British Army had pushed a perimeter away from the Barons Hotel by about 300 metres.

“If they hadn’t pushed that perimeter further out we’d be in a worse place,” he added.