Welcome back, Theresa May—now, here's what you need to do about Brexit

Welcome back, Theresa. You took an especially long holiday this summer. When you returned you had a very silly idea, which was to insist you'd continue as prime minister indefinitely. This is not going to happen, but you can do something meaningful with the time you have left. You can deliver a moderate Brexit—one which is fair by those who did not vote for it, as well as those who did.

Firstly, you need to sort out this divorce payment stuff. While you've been away, relations between Brexit secretary David Davis and EU negotiator Michel Barnier have become quite grim. The EU side wants evidence of progress on the divorce payment before we can discuss future trade arrangements. The British side is having a meltdown about it.

You should have done something about this months ago. We always knew we had a time problem and that two years was insufficient for what you were trying to do. Instead of neutralising the EU's time advantage, you embraced it—like it was some weird kind of proof that you'd deliver Brexit. Then you triggered Article 50 without a plan and held a pointless general election during our negotiating window.

The EU was always going to get upset about money. We're a net contributor, leaving during a period of acute financial sensitivity. This should have been one of the negotiating areas where we greased the wheels of progress, using our financial clout to get the Europeans onside on other matters. Instead, we strapped ourselves to the railway line in front of the oncoming train and told anyone who questioned our actions that they were being unpatriotic.

Now, you are in a conundrum. You need to use the divorce bill as leverage in talks about future trade. But the only way you can talk about future trade is if you give up your leverage on the divorce bill.

Luckily, there are possible solutions. You just need to be pragmatic. You could, for instance, avoid the oncoming train by wrapping up a transitional proposal and a divorce bill proposal in one.

Charles Grant of the Centre for European Reform has written a proposal which could form the basis of this kind of settlement. Accept that the UK is going to have a transitional period which goes on for three years and is going to be as close as possible to what we have now, but without voting rights. Now bundle it up with an offer of 10 billion euros a year in payments until we leave.

That should show that there has been sufficient progress to move on to the next stage of talks, without closing down the divorce bill issue altogether. You preserve some leverage for later, build a more workmanlike relationship with Europe and protect yourself from the oncoming train, all in one go.

You will object to this on the basis that free movement and European Court of Justice jurisdiction would go until at least 2022. And you're right, they will. Accept this. Neither Europe's firms nor ours want two major changes to the regulatory status quo—one into transition and another out of it. And even if they did, there's no time to negotiate them. Transition must be as close to EU membership as possible or it is not worth having.

Don't kid yourself that you can get the talks done before that three-year extension is up. You want a comprehensive trade deal for a modern economy with an emphasis on financial services. It took the EU and the Americans years just to sort out equivalency for clearing houses in derivatives trading - let alone a deal across the economy. If you want to cut us off from our largest market, then say so. But if you don't, accept that these talks are highly technical, smothered in politics and set to take a long time. Stop pretending otherwise.

This sort of rational give-and-take plan doesn't really correspond to how you've behaved over the last year. Instead, you wrapped yourself in the flag, played to the Ukip gallery and pretending the country can have everything it wants without compromise.

Patriotism is a fine thing, but patriotism without reason never helped anyone. It's just a temper tantrum. Real patriotism is anchored down in reason. It strategises carefully and thinks at every step about what it says, in case it would reduce the quality of life of those it represents. We need a prime minister who will keep her head about her rather than one who'll binge on nationalism and then worry about the consequences in the morning.

Sober up, take some aspirin and get to work on a pragmatic divorce bill compromise. It's too late to save your career, but it's not too late to save your reputation.