Our Prime Minister is cornered. And our country is more dangerous for it. Brexit has broken her career. It has broken her party. It is disintegrating her cabinet. And with nothing left to lose politically, she is charting a course that means Brexit will break Britain.

This is not the remaking of Britain that was promised to voters at the 2016 referendum. That delusional Tory offer of British imperialist nostalgia can’t be remotely delivered now. As our economy flatlines and much-needed manufacturing jobs from Swindon to Sunderland are needlessly frittered away, there was a very welcome announcement from shadow chancellor John McDonnell on Friday. Labour’s leadership, he indicated, are now moving towards demanding the British public having the final say.

John is no-one’s fool, neither as a politician, nor economic strategist. He well knows the wise words attributed to John Maynard Keynes: “When the facts change, I change my mind.” And Brexit has been a fact disrupter. The Tories, as Anna Soubry has pointed out this week, can no longer be trusted with our economy, not that I have ever trusted them with an economy that works for working people. Nor has John. And after nine years of austerity, neither do the majority of Britain’s people.

John is focused on building trust in Labour’s economic competence. Building an economy which puts first the public interests of the many - not the privatised interests of the few - is John’s preoccupation. So his fresh assessment that a public vote is now a necessary device to reign in the Brexit chaos is advice that deserves heeding.

His is not a lone initiative. Lexiteers on Labour’s back benches are having the political good grace to admit to a change of their minds too. John Cryer, the chair of the Parliamentary Labour Party, has written to his Leyton and Wanstead constituents telling them he will be voting for the amendment by his Labour colleagues, Peter Kyle and Phil Wilson. They are proposing that Theresa May’s deal should be passed on the proviso that the people of Britain should get a “confirmatory” vote on the deal. Unite general secretary Len McCluskey clarified on Twitter yesterday that his union’s policy “allows us to campaign for a people’s vote on the deal.” The looming fact of May’s Brexit no-deal is the change that now makes that campaign possibility a necessity.

So our Labour Party and our labour and trade union movement is now rising to reject as Cryer put it: “an eleventh hour Hobson’s choice between May’s bad deal and a chaotic no-deal.” This is how to do grown-up politics. And grown-ups do change their minds. To say so is straight-talking. It’s honest. It’s politics as promised by Corbyn’s Labour.

Let’s not underestimate the Brexit challenge Jeremy has faced either. Bringing back together Leave and Remain voters wasn’t going to be easy. Slowly but surely he’s doing just that. He has led the opposition in unprecedented defeats of the government. He is leading the fight to subvert May’s no-deal Brexit. He is ably served by shadow Brexit secretary, Keir Starmer, who has skilfully retained all options, including a new referendum.

The ratification by the public of any deal is now the demand Labour must make. It is the neatest solution to achieve a Brexit peace. McDonnell has shown the Labour leadership is prepared to offer the stability our economy needs by stating that the UK will remain in the EU if a deal agreed by the Commons is rejected in a public vote. And this would enable Britain to lead our continental sisters and brothers in the quest for a new social contract in the EU.

Much has been said about the Irish backstop. Too little has been said about the process by which the Good Friday Agreement was approved. Both sides of the divide were asked to ratify the deal, to come together through a public referendum and to vote for peace. It brought a new beginning to the island of Ireland. A ratification Referendum is the route map to a reconciled, post-Brexit Britain. It will ensure Corbyn’s legacy as a man of peace. And it will be Labour’s patriotic gift to our people.

Manuel Cortes is general secretary of the TSSA trade union