Once Article 50 is moved, a clock starts ticking.  And if an extension of the process is not agreed unanimously, a guillotine comes down on it after two years.  It is at this point that the main measures contained in the Government’s proposed Great Repeal Bill will come into effect: the scrapping of the 1972 European Communities Act and the incorporation of EU law into British law.  Even if the Bill has not been passed, the 1972 Act will then be redundant – because the end of the Article 50 process will effect that end.

All this being so, it is difficult to see how Parliament can compel the Government to ensure that Britain remains a member of the Single Market.  Today’s Observer reports discussions among pro-Remain MPs to this effect, involving Ed Miliband and “pro-EU Tory MPs”.  The paper does not name them, but refers seperately to Nicky Morgan and Anna Soubry tabling questions to the Government.  Nick Clegg is also cited.

Of course, MPs and peers are free to vote in any way they wish.  But they cannot instruct Ministers how to conduct negotiations in detail, although they could ultimately bring down the Government were it to defy them.  However, this is unlikely.  Ministers will doubtless argue at this stage that they are seeking the best Single Market access possible, and this is probably enough to keep Miliband and company at bay for the moment.  It is also far from certain that single market membership will be on offer.

Parliament will get its vote on the 1972 Act, assuming that the repeal bill is passed.  It is possible to imagine that it would get a vote on the post-Article 50 deal, assuming that one is in place.  But the choice then would not be between the deal and staying in the EU.  It would be between the deal and no deal – outside the Union.  Pro-Remain peers and MPs may have tricks up their sleeve that Ministers have not foreseen, but the way Brexit works isn’t helpful to them.