A former Royal Marine turned charity director in Afghanistan has warned people will be "left behind" in Afghanistan as he posted an image of his wife's near-empty evacuation flight out of the capital Kabul.

       Paul Farthing, known as "Pen", has been battling to get all 25 staff from his animal welfare charity Nowzad and their families out of the country after the Taliban took control on Sunday.

       On Thursday night, Mr Farthing wrote on Twitter that his wife, Kaisa, had made it on to an evacuation flight out of the country, but shared a image showing an almost empty plane.

       Mr Farthing called the image "scandalous", adding "thousands wait outside Kabul airport being crushed as they cannot get in. Sadly people will be left behind when this mission is over as we CANNOT get it right".

       Mr Farthing told Sky News he and his wife decided to head to Kabul airport at night in order to avoid the crowds of "at least a couple of thousand" people that descend upon the airport each day.

       He said: "Going at night obviously has its own hazards - it was the choice of two evils and thankfully it paid off."

       Mr Farthing, who has vowed not to leave the country until his staff and their dependants are safe, said flights were taking off "regardless of whether they're full or not", adding: "We are going to leave people behind, that is an absolute given".

       It comes as James Heappey, the defence minister, said that 963 people have been evacuated from Kabul on the RAF "air bridge" in the last 24 hours.

       Mr Heappey said: "It keeps me awake at night, it keeps the Secretary of State (Ben Wallace) awake at night, it keeps absolutely everyone here at the Ministry of Defence awake at night - that reality that we won't get absolutely everybody out.

       "But what is in our gift is that, through the extraordinary professionalism of our armed forces, we can get as many people out as possible."

       Mr Heappey added that it was unclear how long the UK evacuation plan would last as it was dependent on the "dynamic" circumstances.

       He told BBC Radio 4's Today programme: "We don't have it in our gift to stay there until absolutely everybody is out.

       "The air bridge could last two more days, five more days, 10 more days.

       "That's why we're working hard to maximise capacity every single day. And there's been extraordinary work by colleagues in the Border Force and in the consular services to make sure that we can get processed as quickly as possible.

       "We're aiming for 1,000 a day, we hope to do more."

       The minister added that the Taliban were not turning people away from Kabul airport, noting: "Where they have done I've heard it's more that they are being officious rather than malicious."

       Ministers have previously denied that barely-filled RAF planes were leaving Kabul.