Boris Johnson’s visit to Afghanistan when a crucial vote was taking place on Heathrow’s third runway cost the British taxpayer at least £20,000, official figures have revealed.

The former foreign secretary was widely criticised for taking the one day trip which was seen as a ploy to avoid having to go back on his promise to oppose the expansion of Heathrow when MPs voted. 

Information released following a freedom of information request from The Ferret, shows that the cost to the taxpayer for three staff to accompany Johnson on 25 June was £19,366.

The foreign office, however, refused to divulge the costs of Johnson’s flights or any other expenses. 

Theresa May had ordered all her MPs to vote in favour of a third runway, which created a dilemma for Johnson, who once said he would lie down in front of bulldozers to prevent construction. 

To escape the vote, due around 10pm, the foreign secretary needed to be far enough from London during the day to not be able to make it back in time but close enough to get back for Foreign Office questions in the Commons at 11.30am the following day.

In response to reports about the cost of the trip, Labour’s Shadow Chancellor John McDonnell suggested Johnson contribute to the costs with some of the £275,000 per annum he has reportedly been paid for his column in the Daily Telegraph.

He said: “Boris Johnson, who once said he would lie down in front of bulldozers to stop a third runway at Heathrow, scuttled out of the country at the taxpayer’s expense rather than honouring his promise to his constituents.

“Perhaps our former Foreign Secretary will consider using some of the money he earns insulting Muslim women with his lucrative £20,000+ a month column to pay back the taxpayer.”

At the time, his decision not to attend the vote, or resign as many thought he should, came in stark contrast to the Greg Hands, who resigned las a trade minister so he could vote against expansion. 

The Tory MP told MPs: “This is not just for me a debate about Heathrow, important though that is; it’s also a debate about being true to your word and to your election pledges. This vote is also about integrity and the promises we make to our voters.”

Earlier, the former transport secretary Justine Greening, who has also been a vocal opponent of the Heathrow expansion, tweeted to Hands that she “wouldn’t want any long term MP campaigners against Heathrow expansion to miss their chance to represent their community”.

The Scottish investigative news website requested the full cost of the trip as well as dates of when discussions to go began.

The Foreign Office refused to answer most of the questions, citing exemptions under the Freedom of Information Act (FOIA).

The only information they disclosed was the cost to the tax payer for three staff to accompany the then foreign secretary. This included three flights at £6,322 each, a total of £18,966. 

They said the cost of sending Johnson would be published “in due course” on the Foreign Office’s website.