It is a big moment for the PM and the UK at lunchtime when she sets out how she sees the UK’s future commercial relationship with the EU.
The twin big fears that she - and the rest of us - will have is whether her plan has come too late to significantly influence the rest of the EU and if it has been shaped too much by what holds her cabinet and party together, rather than what EU leaders would see as a sensible starting point for talks.
In other words, the risk is that when EU leaders announce the negotiating guidelines for trade talks in just three weeks, these will reflect the Michel Barnier/Donald Tusk entente.
That could mean that because of May’s red lines on the ECJ, migration, the right to negotiate third-party trade deals, and so on, the best the UK should get is a shallow and narrow free trade deal, modelled on Canada’s.
The danger is that, at this juncture, EU leaders see her desire for a special and deep bespoke deal as too much cherry-picking to garnish the cake we want to have and eat.
Which doesn’t mean it is all over and we should reconcile ourselves to a crisis on the Northern Ireland border, or multinationals shifting more jobs and capital abroad, or financial firms relocating to New York.
But if the EU’s negotiating guidelines for talks do rule that the parameters specified today by the PM are 'ultra vires' (beyond her legal powers) and improper - and especially if they see her desire for specific sectoral arrangements as cutting across their imperative of having cross-sectoral rules on issues like data protection and environmental damage - then we will be in for months if not years of wealth destroying uncertainty about a commercial relationship that matters more to the UK than any other.