Prime Minister Theresa May’s efforts to stitch-up a Brexit deal with hard-left Labour leader Jeremy Corbyn have ended in failure.

“I believe the talks between us about finding a compromise agreement on leaving the European Union have now gone as far as they can,” Corbyn wrote to Mrs May in a letter reported by the BBC.

The Prime Minister’s own preferred treaty with the European Union would have locked Britain into a lengthy “transition period” with the bloc in which it would have remained an EU member-state in all but name — minus British representation in EU institutions — possibly followed by an indefinite “backstop” relationship in which Brussels would have retained control over British trade policy and swathes of its regulations, with no power to end this relationship unilaterally.

Labour had initially been seeking to water down this version of “Brexit” even further by establishing a full customs union with the EU, which the Remainer-dominated Tory leadership seemed ready to consider — but subsequent attempts to force May into accepting a “confirmatory vote” (second referendum) as well appear to have been a bridge too far.

“[W]e haven’t been able to overcome the fact that there isn’t a common position in Labour about whether they want to deliver Brexit or hold a second referendum which could reverse it,” May said.

Government Whip Resigns over May’s Decision to Delegate Brexit to ‘Calamity’ Corbyn https://t.co/f7nhfi1zSl — Breitbart London (@BreitbartLondon) April 3, 2019

Corbyn later claimed that his team had negotiated “in good faith and very seriously, and put forward a lot of very detailed arguments”, but explained that the fundamental issue was “that the Government has not fundamentally shifted its view and the divisions in the Conservative Party mean the Government is negotiating with no authority and no ability that I can see to actually deliver anything.”

It is true that Mrs May’s government is a minority administration, reliant on Northern Ireland’s Brexit-supporting Democratic Unionist Party (DUP) to get legislation through Parliament — but it does not back her deal, and nor do a large number of Brexiteer Tory MPs known as “The Spartans”.

Following disastrous results in the English local elections and European Parliament election polls indicating that the Tories have slumped to just 9 per cent public support, the Prime Minister has reportedly been forced to agree she resign by the end of June by the infamous “men in grey suits”.

In Corbyn’s view, this adds to the sense that “the position of the Government has become ever more unstable” — as Mrs May’s successor could refuse to be bound by the terms of a May-Corbyn deal.

Six Days to Go: Brexit Party Hits 35%, Tories on 9%… https://t.co/23d40WlARm — Breitbart London (@BreitbartLondon) May 17, 2019

Follow Jack Montgomery on Twitter: @JackBMontgomery