It sounds like a simple question: how many British nationals, Afghan allies and other people eligible to come to the UK are still waiting to be evacuated from Afghanistan?

With just days to go before the 31 August deadline and the Defence Secretary Ben Wallace warning yesterday that “not everyone will get out” of the country, it’s becoming increasingly urgent.

Yet no-one in the UK government seems to be able to answer it.

We approached the Ministry of Defence (MoD) on Tuesday, who advised us to contact the Foreign Office. The Foreign Office gave us a statement, but it only told us how many people had been evacuated – not how many people were still waiting, as we’d asked.

After a further request from FactCheck, the Foreign Office invited us to approach the MoD, who told us for a second time that they “don’t hold these figures”.

We went back to the Foreign Office, who referred us to MoD stats on the number of people who have been evacuated. We explained that, yet again, this is not what we’re looking for.

We asked the Foreign Office whether the government has estimates for the number of British nationals, Afghan allies and other at-risk people eligible for evacuation are still waiting in Afghanistan. A spokesperson told us: “Our staff are working tirelessly to facilitate the swift evacuation of British nationals, Afghan staff and others at risk. The scale of the evacuation effort is huge and we have helped more than 10,200 people leave Afghanistan since 13 August.”

Any other sources?

On Monday morning, the Defence Secretary Ben Wallace told the BBC: “We estimate around 3,000 [people] in front of the gate that we need to bring people through” in Kabul airport. It’s not clear how many of those people were expected to be eligible for UK airlifts.

But in any case, it seems the figure has grown since then. The Times reported this morning that ministers are “scrambling to airlift more than 4,000 UK nationals and Afghan citizens out of the country by the end of the week”. Of those, the paper says, some 1,250 are British nationals “and other people from recognised ‘safe’ countries”, while the remaining 2,500 are Afghans who have supported British forces since the coalition invasion in 2001.

It’s not clear from the article where these figures come from and the Foreign Office did not respond to our questions about the report.

Separately, the Guardian reported this afternoon that 2,000 “Afghan interpreters and others who worked for the British government are still to be airlifted out of Kabul by the RAF”, attributing this to “defence sources”.

That’s lower than the 2,500 figure reported by the Times – though it’s possible that the figures were updated in the four hours between the two reports.