London (CNN) Over the past few days, the Brexit endgame has become a little clearer. And unfortunately for anyone forced to watch, it looks like it's going to go right down to the wire.

On Tuesday night, Prime Minister Theresa May's chief Brexit negotiator, Olly Robbins, was caught indulging in a bit of late-night loose talk in a Brussels hotel bar. According to Britain's ITV News , Robbins told colleagues that UK lawmakers will ultimately face a choice between the deal brokered by May, or a long delay to Brexit.

For what it's worth, the ITV News reporter who overheard the conversation, Angus Walker, says he didn't hear Robbins in full, nor did he claim Robbins was expressing anything other than his personal opinions. The UK government has made clear that even if the comments were accurately reported, Robbins was not speaking on its behalf, and it remains committed to leaving the EU on March 29.

Nevertheless, the most significant part of Walker's report is Robbins' alleged view that the fear of extending the Article 50 process would focus the minds of Brexiteer-minded Members of Parliament.

Step back 24 hours, and HuffPost UK's Paul Waugh published a detailed and impeccably-sourced essay , reporting that May was warming to the idea of a no-deal Brexit. The logic is that if May concedes too much ground to the opposition Labour Party, as has been suggested of late that she might, it would tear her own Conservative Party apart.

Here's where the Brexit endgame starts to become clear. Both the Robbins calculation and the no-deal scenario rely on a relatively strict calendar: British and EU negotiating teams meet before the end of February; May puts whatever comes of that to MPs on for a vote on February 27; May meets EU leaders at a summit on March 21, leading to agreement just before the Brexit deadline of March 29.

The most important date here is March 21. EU leaders will meet in Brussels and must take a decision whether to agree some new type of deal with the UK -- which May would then have to take back to the House of Commons -- or refuse to reopen the deal. That would land everyone back to square one, just eight days before Brexit.

These eight days are shaping up to be the most crucial in the entire Brexit process. Whatever happens on March 21 (providing Parliament doesn't mandate on February 27 that May ask for a extension to the Brexit process), things will get very crunchy in London.

After this, Parliament will have to approve a deal -- likely something that resembles May's current agreement with some minor tweaks -- or, as per the terms of Article 50, face the reality of the default no-deal Brexit on March 29.

JUST WATCHED Brexit could create costly border delays Replay More Videos ... MUST WATCH Brexit could create costly border delays 03:04

Here we must come back to the overheard comments of the UK's chief negotiator. While many have interpreted Olly Robbins' remarks as some kind of Downing Street plot to terrify Brexiteer MPs into accepting May's deal, it's just as likely that Robbins was stating a political reality. At the end of March, days away from the default no-deal exit, MPs would have to engage with the real world. Plenty of sensible minds think that a majority of MPs would, at that point, do all they could to avoid chaos and force May to request an extension to Article 50.

Now that really would concentrate minds. Hate the idea of no-deal? Vote for May's deal. Terrified of Brexit delayed? Vote for May's deal. Call it the lesser of three political evils.

And the real drama lies in the fact that it's not clear if this is all part of some grand Downing Street plot. In an excellent Politico piece earlier this week on the inner workings of May's mind, Tom McTague concluded: "The woman who runs Britain in its gravest hour of crisis since 1945 remains almost uniquely unknown for a prime minister."

McTague hammers home the point that, in the event that May's deal is scuppered -- either by the EU or by the UK Parliament -- it's not clear how she would react. Faced with the choice between embracing a no-deal Brexit or requesting a last-minute delay, "no one knows which way the Prime Minister would jump in this scenario: Not her Cabinet, her closest advisers nor her lifelong friends in parliament."

In other words, for all who oppose May, the threat is real. Optimists in London believe that May could yet pull off the seemingly impossible and bring enough MPs on side to get her deal approved. Although it should be noted that most of the optimism is confined to members to May's team and their supporters.

Not everyone else is so confident. In Brussels, people close to the negotiations are increasingly worried that a small group of hardline MPs in London are starting to convince colleagues that a no-deal scenario would not be the disaster many are predicting. The problem is, so few in Brussels trust anything that is said by Westminster politicians any more. "The risk of a disorderly Brexit is rising. It's impossible to tell if these people are just grandstanding, or if they have started to believe that no deal is actually the best option," an EU source with detailed knowledge of the negotiations explained.

So as with all things Brexit, miscommunication and a failure of one camp to understand the other takes the UK ever closer to the knife edge. There are five weeks to go until the March 21 summit. Expect plenty more eruptions before then. But remember, very little changes the decision that MPs will ultimately have to make at this point.

Time has backed the UK into a corner.