In answer to a question from Ed Miliband about how the transition period will differ from membership of the single market and the customs union - given that she has stated unequivocally we will leave both in March 2019, the PM said (HERE Hansard Column 49) on Monday:
"I have to say to the right hon. Gentleman that, as we leave the European Union in March 2019, we will leave full membership of the customs union and full membership of the single market. What we then want is a period of time when practical changes can be made, as we move towards the end state—the trade agreement—that we will have agreed with the European Union. We have to negotiate for the implementation period what the arrangements would be. We have suggested that that should be a new agreement—an agreement that we should be able to operate on the same basis and on the same rules and regulations".
So just to clear that up:
1. In March 2019, we will leave full membership of the customs union and full membership of the single market.
2. We should be able to operate on the same basis and on the same rules and regulations.
In other words we will be leaving the EU but behaving as if we haven't. This is not too far removed for the EU negotiating guidelines produced in April but note they say (paragraph 6):
Should a time-limited prolongation of Union acquis be considered, this would require existing Union regulatory, budgetary, supervisory, judiciary and enforcement instruments and structures to apply.
So, although she told Jacob Rees Mogg that, "Yes, that may mean that we start off with the ECJ still governing the rules we are part of for that period" I think she knows we will be subject to ECJ jurisdiction for the whole of the transition period and this will probably be much longer than two years.
Mrs May seems to be slowly but surely giving way on everything but it's taking an awfully long time. It seems as if she believes doing it at glacial speed will avoid upsetting the mad Brexiteers, and there is some evidence it's working. As each concession happens there is a lot of initial noise but it soon becomes accepted wisdom with even The Sun now saying they can wait a bit longer.