Britain’s Foreign Office abandoned many of the nation’s allies in Afghanistan and left them to the mercy of the Taliban during the fall of the capital, Kabul, because of a dysfunctional and arbitrary evacuation effort, a whistleblower alleged on Tuesday.

In devastating evidence to a parliamentary committee, Raphael Marshall said thousands of pleas for help via email were unread between Aug 21 and Aug 25.

The former Foreign Office employee estimated that only five per cent of Afghan nationals who applied to flee under one UK programme received help. He said that at one point, he was the only person monitoring the inbox.

“There were usually over 5,000 unread emails in the inbox at any given moment, including many unread emails dating from early in August,” he wrote to the Foreign Affairs Select Committee, which is investigating Britain’s chaotic departure from Afghanistan.

“These emails were desperate and urgent. I was struck by many titles including phrases such as ‘please save my children’.”

Marshall said some of those left behind had been killed by the Taliban.

Soldiers put at risk to save animals

One of Marshall's most explosive allegations is a claim that British officials spent time and energy arranging the evacuation of almost 200 dogs and cats from a Kabul animal shelter run by Nowzad, a charity founded by former Royal Marine Pen Farthing.

Marshall claimed Foreign Office staff had received an instruction from the prime minister to use considerable capacity to transport Nowzad's animals. He claimed British soldiers were put at risk to get the animals out of Kabul.

Prime Minister Boris Johnson's spokesman, Max Blain, said the allegation was entirely untrue and neither Johnson nor his wife Carrie, an animal-welfare advocate, had been involved in helping the animals leave.

He said Farthing and his animals left Afghanistan on a privately chartered plane which was given clearance by British officials.

"We are confident that at no point clearance for that charter plane interrupted our capability to evacuate people," Blain said.

As the Taliban took power in August, the United States, the UK and other countries rushed to evacuate Afghans who had worked with Western forces and others at risk of violent reprisals.

Britain managed to airlift 15,000 people out of the country in two weeks, and the government says it has since helped more than 3,000 others leave Afghanistan.

But an Afghan Resettlement Scheme announced by the government in August with the goal of bringing another 20,000 people to Britain has yet to get underway.

Former foreign secretary Dominic Raab, who was moved from the Foreign Office to become Justice Secretary after the crisis, defended his actions.

“Some of the criticism seems rather dislocated from the facts on the ground, the operational pressures that with the takeover of the Taliban, unexpected around the world,” he told the BBC.

“I do think that not enough recognition has been given to quite how difficult it was.”

Tom Tugendhat, a Conservative lawmaker who heads the foreign affairs committee, said Marshall’s testimony “raises serious questions about the leadership of the Foreign Office.”

The committee is due to quiz senior Foreign Office civil servants later on Tuesday.

The Taliban stormed across Afghanistan in late summer, capturing all major cities in a matter of days, as Afghan security forces trained and equipped by the US and its allies melted away. The Taliban took over Kabul on Aug 15.

Many who had worked for Western powers or the government worried that the country could descend into chaos or the Taliban could carry out revenge attacks against them.

Many also feared the Taliban would reimpose the harsh interpretation of Islamic law that they relied on when they ran Afghanistan from 1996 to 2001.

At the time, women had to wear the burqa and be accompanied by a male relative whenever they went outside. The Taliban banned music, cut off the hands of thieves and stoned adulterers.