Theresa May’s decision to reach out to the opposition over Brexit comes years too late. She has only done so because she has run out of road. Her speech from Downing Street shows a prime minister shrunken by defeat. It stood in stark contrast to last month’s defiant rabble-rousing statement delivered from the same lectern. All this sours the idea that Mrs May is approaching discussions with Jeremy Corbyn in good faith. It speaks volumes that it is only with her back to the wall that the prime minister has bowed to sense and accepted that the longstanding arguments of her opponents must be taken on board. The question remains whether her mind is as open as the door to No 10.

Mr Corbyn says he is “happy” to meet Mrs May. He would be right to also be wary. Despite Mrs May’s talk of “national unity to deliver the national interest”, her offer is rooted in Tory partisan politics. There is no indication of any compromise that Mrs May is willing to make. The basis of the proposed negotiation is her Brexit withdrawal agreement, which has already been rejected three times by the Commons. The Labour leader has whipped his party to vote against Mrs May’s deal. He would have to agree to back it now. The suspicion is that Mrs May does not want to share the glory, just the blame.

The prime minister’s bid to resolve the crisis also seeks to cut the ground from beneath the feet of backbench MPs who had aimed to take control of a process when Mrs May could not. A cross-party group, led by Yvette Cooper and backed by Oliver Letwin, had been prepared to place a bill before the Commons to force the prime minister to seek an extension of article 50. They were right to do so. Crashing out of the EU without a deal would be extremely damaging to Britain. In contrast to the trite “clean break” scenarios, there are warnings of food prices spiking upwards, businesses collapsing and peace in Northern Ireland being put at risk. Hard Brexiters, who revel in their classical training, seem to be living up to the ancient idea that whom the gods would destroy, they first make mad.

In exchange for Mr Corbyn’s support, Mrs May offers Labour a chance to shape the future end state of Brexit. If the leaders were unable to agree “a single unified approach”, the prime minister appears willing to agree a number of post-Brexit options and then allow MPs to vote for them. It is unclear whether these would be free votes or whipped, but Mrs May says she will abide by them – if Labour does. This is responsibility without power for Mr Corbyn. It raises the question of why he would accept such a bargain. Mrs May has already promised her MPs she will resign once this process is complete. There is no guarantee that her successor would be bound by deals she had done with Labour. A truly collegiate process would require something more substantial to negotiate a broad and deep future partnership with the EU once Britain had left. But that would not fly with the hard Brexiters.

What is true is that Brexit remains an idea in search of an adequate mode of expression. Like a soul without a body, its wraith-like form hangs over the Commons, freezing the blood of the body politic. Because it remains intangible, Brexit can bore and terrify the public at the same time. To give it meaning and substance, much more time is needed for Brexit to be reimagined. Yet Mrs May leads a party in which a substantial minority view such a practical move as so inimical to their identity that it borders on treason. She faces a mutiny for suggesting talks with Labour.

The EU has said it would only accept an extension if Mrs May presented a way out of the current mess. As she leads a minority government, it ought to have been obvious that she needed cross-party support. In leaving it so late and in setting these terms, Mrs May is playing with fire. If there is no prospect of agreeing a form of Brexit and if there is no extension forthcoming, the UK will either have to revoke article 50 or depart with no deal a week on Friday. Should the country face that predicament, it will be Mrs May’s fault.