More than 40 former senior diplomats have called on Theresa May to delay Brexit and hold a second EU referendum.
A total of 43 ex-ambassadors and high commissioners have written a joint letter demanding the prime minister not allow the UK to leave the EU “when we have no clarity about our final destination”.
Their intervention, organised by the People’s Vote campaign for a second EU referendum, comes with just 43 days until the UK is scheduled to leave the EU and with Mrs May facing the prospect of another embarrassing Brexit defeat in the House of Commons.
The prime minister has repeatedly ruled out holding another EU referendum, having spoken of her determination to “deliver Brexit on time” on 29 March.
But her chief Brexit negotiator Olly Robbins was, according to recent reports, overheard revealing a plan to present MPs with a choice between the prime minister’s deal with Brussels or a long delay to Brexit.
Mrs May played down suggestions of such a scenario, telling MPs on Wednesday: “We want to leave with a deal – that’s what we’re working for.”
Among the signatories of the letter are former ambassadors to the US, UN, Russia, Germany, France and Ireland.
Lord Kerr, a former ambassador to the US and one of the authors of Article 50 – the exit mechanism by which a member state leaves the EU – also added his name.
In the letter, the ex-diplomats said there is a “powerful argument” for “going back to the people” to give them a choice between Mrs May’s deal and remaining in the EU.
“Our country’s national interest must always be paramount,” they wrote.
“The Brexit fiasco has already weakened the UK’s standing in the world. We strongly advocate a change of direction before it is too late.”
Parliament is currently in deadlock over the EU divorce deal Mrs May agreed with Brussels in November, having overwhelmingly rejected her withdrawal agreement last month.
However, a majority of MPs have signalled they will support a Brexit deal if the backstop arrangement within the prime minister’s deal, aimed at avoiding a hard border on the island of Ireland, is altered.
A majority of MPs have also said they are opposed to the UK leaving the EU without a withdrawal agreement, known as a no-deal Brexit, albeit through a non-binding vote.
The number of MPs who have declared their support for another referendum currently remains too small to win a majority.
Regardless of whether a deal is ratified before 29 March, the UK is on course to leave the EU automatically under current legislation.