Compromise will be the name of the game as prime minister recognises enormity of task

If Theresa May’s first two speeches unfurled the promise of a “red, white and blue” Brexit, a cold grey day in March will be remembered as the moment a more faded flag was fluttered.

As the nation took shelter from the beast from the east, this was intended to be May’s “reality bites” speech. Ten times she used the word “recognise” to underline she no longer believed Britain could have it all.

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“We recognise that we cannot have exactly the same arrangements with the EU as we do now,” she said. “We recognise this would constrain our ability to lower regulatory standards. We need to face up to facts. Our access to each other’s markets will be less”.

Little wonder that by the time it came for questions, and a German newspaper asked: “Is it all worth it?” The prime minister had to pause awkwardly before replying: “We are not changing our minds.”

Much attention will focus on the remaining chasm between Downing Street’s hopes and the increasingly intransigent position adopted in Brussels. There was little to explain how they might solve the current crisis over Northern Ireland in the three weeks allotted.

It would be churlish though not to acknowledge creeping realism from a politician whose heart has never really seemed in it. The weary call for “pragmatic common sense” was directed at both her own party and Europe.

They seemed receptive. “I welcome [the] speech,” the EU’s chief negotiator, Michel Barnier, said. “Clarity about leaving the single market and customs union and a recognition of trade-offs.” Jacob Rees-Mogg’s European Research Group was said to be “very relaxed”.

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So the Mansion House speech deserves a thought experiment. What if the prime minister pulls off the compromise she now admits is the best on offer? What do the bright colours and red lines look like when they have been through the wash a few times?

Her first admission was that much of Britain’s reclaimed sovereignty would remain theoretical. In order to maintain market access for industrial goods, any future Westminster government would need to apply almost identical trading rules. Yes, they could decide not to, one day, much as Brexit itself is proof of parliament’s ultimate veto already, but it would swiftly bring the borders crashing down.

Secondly, May’s convoluted proposals for avoiding a customs union would rest on the most intrusive and bureaucratic system of government monitoring yet devised. Imports would need to be tracked long after entry in order to make sure they were destined for UK or EU customers. If the Irish border is solved, it will be by turning a blind eye to thousands of small acts of smuggling and law-breaking.

This would also be a fragile truce. Despite promising any solution had to be permanent, the system of mutual recognition that May envisages for sectors such as banking and television could break down at any moment. Industries such as medicines, aviation and chemicals would remain largely under Brussels’ control, but farming, fishing and computing would remain outside its reach – for now.

There is the potential for many further climb-downs too. Where before there were promises, May now offers tests. Among others, Brexit would only be a success if it “protected prosperity”. The unspoken threat being that if this looks in jeopardy, it might be time to revisit more red lines.

“There will be ups and downs,” May said. “But we will not be buffeted by demands to talk tough ... or accept the counsel of despair that this cannot be done.”

An endurance test without end, she might have said, for a purpose only in itself.