Here we go into the rabbit hole … what will be the meaning of the promised "meaningful vote" of Parliament about the conditions of every Brexit deal that Theresa can conclude with the EU?
This is a question that takes its asker to the heavily mined, crater-dotted no man's land that lies between the parliament and the government.
How did we get here?
Just before Christmas, MEPs amended the EU Enforcement Act to make the government in effect make Brexit impossible until they put the thumbs for each deal (along with the parallel political statement on the long-term UK-EU relationship) and the government assured that Parliament that would have a "meaningful vote".
But it is not even clear to MPs, let alone to the general public, how the parliamentary votes to make this fateful decision will be structured.
So this week the Commons Procedure Commission started an attempt to route a route through this extremely dangerous terrain. The committee has some merit in this area, after setting up a system for monitoring changes to the law made under the extensive powers of the Brexit legislation, and defended it when it seemed as if ministers were covering one aspect of the new control system. tried to weaken.
But this time their efforts caused an explosion of anger.
- Commons Brexit vote must be & # 39; unambiguous & # 39; to be
- Commission procedure: withdrawal agreement Invoicing for evidence
The immediate cause was the publication of a memo from the Brexit secretary, Dominic Raab, which explained how the government thought the sensible vote would work. His main point was that there would be no legal uncertainty as to whether Parliament had voted appropriately on the deal (parliamentarians will approve it, colleagues only need to "notice").
The big stumbling block is that Parliament can not change the withdrawal agreement itself, because it is an international treaty negotiated with the EU.
If it wants changes, the British ministers must go back and try to negotiate them.
Neither, says Mr Raab, can Parliament postpone or prevent the departure of the UK because they are already enshrined in British law and by the Article 50 process enshrined in EU law – although this point will soon be in court. will be tested. Mr Raab's memo states that an amendment would undermine the government's ability to ratify the revocation agreement.
On the basis of that logic, he argues that the real question that MEPs will face is a simple "yes-no" – whether or not to accept the deal that Theresa May draws from Brussels.
In that case, he adds, the normal form of Commons that votes, where amendments are made, some are selected by the Speaker, and voted on before the main approval movement (perhaps at that time changed, somehow amended) has been submitted to Parliament, is the wrong way.
So his memo rejects the normal method and benefits a procedure based on the way opposition day motions are considered – the main motion is voted first and only when it is lost do MPs turn to alternatives.
The point is that the Raab approach is a much more difficult choice, especially for potential conservative dissidents. It is one thing to support an amendment that weakens (or even hardens), regardless of what the government proposes, to pass it on and then to support the resulting proposition; it is rather different to put the government deal to the vote and then see what could happen next.
Is this the determination of the decision? The author of the meaningful vote last December, the former Attorney General, Dominic Grieve, rejects Mr Raab's concerns with a negative Anglo-Saxon monosyllable – and Labor has his proposal as a flagrant solution rejected.
So MEPs are now in a situation where it will be even more difficult to find an agreed method to make this critical decision, and the procedure committee is now in the limelight. And next week a serious backlash against Mr Raab could be seen; especially look at the other Dominic, Mr Grieve.
What if MPs rejected the Brexit deal?
But what if – according to the Raab procedure or in some other way – MEPs voted to reject the Brexit deal?
It is not clear what impact any subsequent votes would have. They could adopt an amendment calling on the government to renegotiate a certain aspect of the withdrawal, but they could not guarantee that preachers could achieve the desired result, or even work very hard. They could demand a second referendum – but to make that stick, they had to adopt a fully-fledged law of parliament; a simple resolution, which claims to direct the government, should not cut the mustard.
Parliament and its existing procedures for debate and decision are not really geared to policy – they control policies and make laws, but it is much more difficult for MPs to instruct ministers, and even more difficult for them to keep their instructions, unless they have passed as legislation.
The former Lib Dem MP and Professor of Constitutional Law, David Howarth, have argued that the ultimate weapon available to parliamentarians is to insist on the old parliamentary principle of "pre-delivery complaint" and to refuse to pass the next Finance Act. until the government makes a further commitment. Brexit referendum.
Others think that is a bit fanciful, but the upcoming budget and the subsequent Finance Bill will provide a serious lever for those who are not satisfied with the government's position.
This can be done by something very procedural, such as tampering with the program movement, which would be a timetable for the revision of the Chancellor's tax changes – but faced with increasing factional dissatisfaction of his internal Leavers and Remainers, and of his DUP allies, the government is now dangerously vulnerable.