British Prime Minister Theresa May is out of time. Her government has struggled for over two years to patch together an organized plan for the United Kingdom to leave the European Union. She'll have another, perhaps final chance to present her ideas to Parliament today — but at this point, it should be obvious that hers is a fool's errand.

May has in fact crafted an organized Brexit plan that was stamped with the EU's approval. The problem is that everyone in May's own country hated it. The British Parliament rejected her plan back in January by a historic 230-vote margin. May has been negotiating with the EU since to try to win further changes that might make the proposal palatable to Parliament. On Monday night, she returned from last-ditch talks with the EU with "legally binding" changes to the deal that she "passionately believed" would appease her critics in Parliament.

Come hell or high water, Britain will leave the EU on March 29 — just 17 days away. Between now and then, three more parliamentary votes are scheduled.

The first actually happens on Tuesday and is basically another vote on May's deal, and the changes she's secured. This new deal apparently addresses the Irish border backstop, and assures that Britain will not be stuck in EU rules and regulations indefinitely. This was a sticking point for many MPs, so there's hope the new deal will pass in Parliament. But despite May's perseverance, there's still every reason to expect her plan will go down to yet another defeat. The only question is how brutal it will be.

The second vote is scheduled for Wednesday and will decide whether Parliament wants to go ahead with a no-deal Brexit instead. In this scenario, Britain leaves the EU with no pre-set plan at all. Almost everyone agrees this would be a disaster.

It's not hard to see why. Right now, the rules and regulations that govern the flow of people, goods, and services between Britain and the other EU countries is governed by EU laws. It's basically an open market, with minimal restrictions. Once Brexit happens, there needs to be new rules and regulations to govern the new relationship. That's what May's plan is supposed to provide. What happens without it?

Both Britain and the rest of the European Union are members in the World Trade Organization (WTO), which lays out some baseline rules for tariffs and customs and regulations. They're meant to govern in the absence of any other agreement between two member countries. The widespread assumption is that Britain and the EU will just revert to the WTO standard with a no-deal Brexit, as would Britain's trade relations with many other countries.

Unfortunately, WTO rules dictate higher tariffs and more onerous customs regulations at the border, so trade between Britain and the EU would become more expensive and much slower at a stroke. Even worse, it's not even obvious a reversion to WTO rules is automatic. Britain might have to pass a whole bunch of new laws to implement that reversion. In which case, March 29 doesn't bring worse rules; it brings pure chaos.

Needless to say, a no-deal Brexit will get voted down as well.

That leaves the third vote, on Thursday, which is about whether to delay Brexit. Any such reprieve is unlikely to last more than a few months, though: Everyone wants to settle matters before the new term for the European Parliament begins in July, after the May elections. Still, this measure seems more likely than the other two to pass. British policymakers will probably take whatever extra time they can get. The EU even sounds inclined to agree to an extension, as long as there's a clear endgame in sight.

What could that endgame be?

After two and a half years, May couldn't cobble together an agreement that a majority of British policymakers and the EU can all sign onto. What new ideas or proposals could possibly emerge in the next two or three months that would change everyone's minds? The only other possibility is that Britain explicitly agrees to use the extra time to put together a second Brexit referendum, giving its citizens a chance to call the whole thing off.

Britain has never organized a referendum on such a short time table. But at least some British legal experts argue it could be done, if the government really put its mind to it.

A second referendum to cancel Brexit carries a whole host of risks in its own right, including failure, a perception of political illegitimacy, even political upheaval.

But if Parliament rules out a no-deal Brexit, it might just be the only option left.