Theresa May has said she will prove to be 'bloody difficult' when negotiating with Europe. For a woman who wants to play her hand close to her chest this is a remarkable admission to make.

Many is the time I have gone into a negotiation working with a partner and have agreed in advance who is going to play the nice and nasty guy, or the reasonable and unreasonable one. Having a good and bad cop makes sense. One has to make the undeliverable demand. The other has to be the one who reaches out to find the compromise that will, inevitably, form the basis of an agreement. At the end even the bad cop will have been persuaded to come round to the party line. Judging when to do that is another key part of the process.

But, and it's a big but, this requires that the other side do not know in advance who will play which role, especially if the discussion is part of an ongoing debate. Swapping roles is disconcerting, and because there will always be multiple issues in a negotiation, easy to achieve without appearing inconsistent. It leaves the other side guessing. More than that, it allows for flexibility.

But May has now cast herself as the unreasonable person in the Brexit negotiations. It's a role she will find it hard to escape from now she has stated it so publicity. And this then requires that there be a perpetually reasonable person to be beside her, predictably being the compromiser trying to find the solution. Three problems arise.

The first is the tactical error of declaring this to be her role. All surprise is gone.

The second is the fact that she should most often be the compromiser, coming in to solve the irreconcilable positions her more junior negotiators have created for her and looking good in the process. That, after all, is her goal.

The third problem is I simply can't think who the nice guy is in this case.

To describe this as incompetent is to be polite. But I can be the nice guy.