"So does that mean we won’t have any trees?” The question posed by 21-year-old Hayley Hughes on Friday’s episode of Love Island has inspired much mirth and helped to ensure that the contestants’ impromptu discussion of Brexit has already become one of the year’s most unlikely viral clips.

“That’s got nothing to do with it, babe,” explained the group’s self-appointed constitutional expert, Georgia Steel. “That’s weather.” There remains a school of thought that Hayley was in fact asking about “cheese” rather than “trees” — on the basis that continental dairy products may be harder to get hold of after March 29, 2019. Whatever the truth of the matter, she admitted: “I seriously don’t have a clue.”

But before you join in the scorn — if you haven’t already — ask yourself this: do you really know much more than the confused model about the form that Britain’s prospective departure of the EU will take and the impact that it will have? As blithely as you might, from time to time, hold forth about the Irish border, “backstops”, “meaningful votes”, transitional arrangement and frictionless borders, do you honestly know what is going on? Is it not possible that the universally-mocked Hayley speaks for Britain?

This week, as more than two million viewers tuned in to Love Island, a considerably smaller number of obsessives have been tracking the passage of the European Union (Withdrawal) Bill through the House of Commons, while MPs wrestle with the amendments sent to them by the House of Lords.

Yesterday the Government prevailed in 11 such votes and avoided a division altogether on one other amendment. With her usual mix of political Sellotape, procrastination and textual ambiguity, Theresa May saw off yet another moment of grave danger to her premiership and — for what it’s worth — kept the shambolic Brexit show on the road.

But it would be a brave or foolish observer who declared with confidence that the past two days have offered anything approaching clarity about the likely character of Brexit. As so often, the Prime Minister has lived to fight another day by postponing the difficult stuff, keeping resolution at bay, and turning equivocation into an art form.

Yesterday’s debate on the “meaningful vote” promised to MPs on the exit deal was the perfect dramatisation of this political method and its perils. The question posed by the former Attorney General Dominic Grieve was wrapped up in technicalities but, at heart, could scarcely have been simpler: if the Commons rejects the agreement reached between the Government and Brussels — assuming there is one — who, then, is in charge? Does the UK crash out of the EU without a deal of any sort, or does Parliament take the reins and compel ministers to do better?

By resigning unexpectedly yesterday as Justice Minister, Phillip Lee triggered hours of confusion and panic in No 10, until a meeting between May and the potential rebels — nicknamed “the Ag-Grieved” — ended with a compromise of sorts.

This was nothing less than constitution-writing on the hoof: settlement of the most subtle issues of institutional balance, according to the rules of speed-dating. And, unsurprisingly, nobody can agree what has been signed off.

"As so often, the Prime Minister has lived to fight another day by postponing the difficult stuff"

The Grieve gang believes that the Government itself will now table a fresh amendment which — in the event of Parliament rejecting the final Brexit deal — would mandate ministers to set out a new plan within seven days; and in the case of talks with Brussels breaking down give the Government until November 30 to seek a new agreement. Most ambitious of all is the suggestion that, in such circumstances, Parliament would assume control of UK diplomacy and direct ministerial conduct from the Palace of Westminster.

Not surprisingly, this is not how the Government interprets what it has conceded. No sooner had the truce been reached than the Department for Exiting the European Union declared: “We have not, and will not, agree to the House of Commons binding the Government’s hands in the negotiations.” As Steve Baker, the Brexit minister, elaborated: “It is a constitutional innovation which would be totally unprecedented. You cannot have 650 MPs conducting the negotiation.”

Much as I prefer parliamentary democracy to the crude populism that the referendum result has unleashed, Baker is absolutely right. It is not the case, as is so often asserted, that Parliament is sovereign. That distinction is accorded to the Queen-in-Parliament, which is to say the sovereign and her ministers acting in concert with MPs and peers.

According to this arrangement, the Cabinet is, as Walter Bagehot wrote, “a combining committee — a hyphen which joins, a buckle which fastens, the legislative part of the state to the executive part of the state”.

Parliament makes laws and holds government to account but it does not govern, or assume the prerogative powers of the executive. This is why the proposal that every military action should be pre-authorised by the Commons — by law or convention — is practical and intellectual nonsense. The job of MPs is no more to oversee every operation undertaken by the armed forces than it is to give diplomats in Brussels their instructions.

This is the sort of mission creep that gives a bad name to the precious idea of parliamentary scrutiny. It is a grave category mistake. And it will not stand. It is inconceivable that the Government will be able to tolerate such a delegation of its day-to-day powers to 650 fractious parliamentarians.

The question of what a “meaningful vote” on Brexit constitutes has not, in other words, been resolved. Nowhere close. May remains in office, Brexit lurches on, but, in truth, nobody has a clue. It turns out that Hayley was right all along.