Brexit: What's next if MPs reject May's deal？

And, yes indeed, there have been many, many times that we have reported that it is a crunch moment, or a crucial day, or a vital moment.

And each mini-drama - each bizarre twist, each day where we have moved further from anything like politics as usual - has had meaning.

That's true of the prime minister's speech in Florence, the meltingly hot cabinet day out at Chequers, Boris Johnson stalking out of the cabinet, or indeed, the EU saying "non, non, non" at Salzburg, or Gina Miller's Supreme Court appeal where on Parliament's behalf - on behalf of all of us in a sense - she won a bigger say over Brexit for MPs.

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Barring an almost incredible to imagine second delay to the vote, Tuesday is when MPs get the chance to express that wish - to say yes or no to the deal that's on the table.

The weird thing about it is that unless, again, something almost impossible to ponder happens, we know that they are in large numbers going to say no.

Parliament taking control

There is precious little jeopardy in saying that, although be sceptical about any predictions about the size of the defeat.

MPs don't even trust each other on rebellions, let alone always stick to what they may brag about before.

If you take a clear "no" vote as read then, there is a possibility that moves afoot to stop us leaving without a deal will be taken by parliamentarians who have been studying the rule books very closely.

Image copyrightAFPImage caption Gina Miller's court case won MPs the right for a bigger say on Brexit

In recent months among the cacophony, Parliament has steadily been taking more and more control of the Brexit process, if not ownership of the problems.

And it's likely this week there will be another attempt, maybe even before the vote, to remove the risk that we can leave without a deal. Of course it would need a majority of MPs to support that (always, always, easier said than done).

But remember even if they do, the immediate question will be: for what？ At the moment there is no majority in Parliament for any plan that has actually been put on the table.

And some cabinet ministers believe the attempt to snarl up the process in that way could be blocked in any case.

If that's so, well, several cabinet ministers from different parts of the Tory party have told me they expect that the prime minister will have at least another attempt to get her deal, or something rather like it, through Parliament.

Quick guide: What is a no-deal Brexit？

A "no-deal" Brexit is where the UK would cut all ties with the European Union overnight.

Theresa May's government, and many others, believe this would be hugely damaging and want a more gradual withdrawal. But if Parliament can't agree on that, and nothing else takes its place, the UK will leave without a deal.

This would mean the UK would not have to obey EU rules. Instead, it would need to follow World Trade Organization terms on trade. Many businesses would see new taxes on imports, exports and services, which are likely to increase their operating costs. That means the prices of some goods in UK shops could go up.

The UK would also lose the trade agreements it had with other countries as a member of the EU, all of which would need to be renegotiated alongside the new agreement with the EU itself.

Manufacturers in the UK expect to face delays in components coming across the border.

The UK would be free to set its own immigration controls. However some UK professionals working in the EU and UK expats could face uncertainty until their status was clarified. The European Commission has said that even in a no-deal scenario, UK travellers won't need a visa for short visits of up to 90 days.

The border between Northern Ireland and the Irish republic would become an external frontier for the EU with customs and immigration controls, though how and where any checks would be made is not clear.

Some Leave supporters think that leaving without a deal would be positive if the right preparations were made. They say criticism is scaremongering and any short term pain would be for long term gain.

But critics - including both Brexit supporters and opponents - say that leaving without a deal would be a disaster for the UK: driving up food prices, leading to shortages of goods and gridlock on some roads in the South East resulting from extra border checks.

But despite her reputation for secrecy, this week she will have to make something clear.

Will she shift to what many in Parliament want, a closer relationship with the EU, perhaps moving across to some kind of customs union？

Or will she ramp up preparations for no deal, trying (which many just don't believe) to show that she really would be willing to walk away with no deal, in the hope that pressure would persuade the EU to crack and make it plain that she is not for turning？

Decisions can't wait

That is likely to be the call she'll have to make. One cabinet minister told me: "This week it distils into what people truly think - between those who are really scared of leaving without a deal, and those who are really scared of not leaving."

Even after all this time, the Tories, and this Brexit prime minister, are still faced with the same fundamental choice there always has been - take the risk of going it alone with a dramatic break from the EU, with all the turmoil that might go alongside it.

Or cleave to a closer relationship with the EU, some kind of customs union by another name, that could tear the Tory party apart.

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Delay is a tactic that has been used by Theresa May with great effect, arguably keeping her - even if unhappily - in office.

Every route that she might choose has risks, perhaps none of the choices are tempting for Number 10.

But on Tuesday night votes will actually be counted - the numbers, and decisions after they come, just won't wait much longer.