Our guide to this week’s Brexit showdown

Two weeks on from the last Brexit showdown in Parliament, Prime Minister Theresa May will once again update lawmakers on progress in negotiations. In truth, it doesn't seem like there’s much new to report.

The EU has reiterated that it will not reopen negotiations on the main withdrawal agreement, so the UK is focused instead on securing some legal guarantees surrounding the contentious Irish backstop. As things stand, there are still big differences between both sides left to be resolved - and while it's possible Brussels does give a few minor legal concessions at the last minute, it seems unlikely that they will be enough to secure the support of a large chunk of pro-Brexit Conservative and DUP MPs.

The upshot is that the Prime Minister now won't attempt a second go at getting her deal through Parliament this week. But as has happened a few times now, on Wednesday she will instead give MPs the chance to have their say on how things are going. May will put forward a motion detailing the latest progress in talks, and lawmakers will get to vote on it and put forward their own ideas on what should happen next (in the form of amendments).

The major focus will be on a proposal that would begin laying the groundwork for a possible extension to the two-year Article 50 negotiating period. The plan, labelled the Cooper-Letwin amendment, would aim to buy more time to find a deal that can unite Parliament, helping to avoid a potentially damaging exit on WTO terms.

Cast your mind back to the end of January, and you might remember a similar plan – labelled the Cooper-Boles amendment - was actually rejected by MPs.

That said, the scale of the defeat was relatively narrow. A number of Conservative ministers and lawmakers were reportedly convinced to reject the plan back then on the promise that they’d get another attempt at extending Article 50, if the Prime Minister hadn’t managed a breakthrough.

One month on, and it looks like this group – which includes senior government ministers – may be losing patience. There have been suggestions of ministerial resignations if the government doesn’t commit to delaying the 29 March deadline this week – Sky even reported last week that one minister has already begun planning his own leaving drinks.

Put simply then, the chances of this amendment passing on Wednesday seem to be growing - although we have been here before. May is hoping to avoid a defeat by promising MPs a final meaningful vote on her deal on 12 March.

In short: no. Even if MPs approve the Cooper-Letwin proposal, it doesn't legally oblige the government to do anything just yet.

Instead, time would immediately be given to allow Yvette Cooper and Oliver Letwin to table a bill that would aim to transpose the proposal into law.

Once passed, the goal would be to set up a showdown in mid-March where MPs would face a two-way choice between no deal and extending Article 50. If lawmakers chose the latter, Theresa May would be obliged to return to Brussels to ask for extra time.

It could still be quite a while before there is clarity on whether 'no deal' has been avoided

Admittedly, this leaves just two weeks to get this bill through Parliament if the vote is to happen on 13 March as hoped. That's a very short timescale to pass any bill, even if the situation is fairly urgent. The legislation will need to pass through the House of Lords as well as the House of Commons, which will take time.

Assuming it can get through quickly though and MPs do ultimately opt to extend Article 50, then the ball will be in the EU's court. Don't forget the UK can't decide to extend Article 50 on its own, it needs EU leaders to agree to it unanimously. All the signs so far suggest Brussels wouldn't object, although there are still big question marks over how long an extension might last.

Given the logistical hurdles presented by European Parliamentary elections, the easiest option might be to grant a short two to three month delay - although there is a real risk this won't be long enough. The Guardian is reporting that the EU is mulling over a 21-month extension to avoid the uncertainty created by a much shorter time-frame.

The upshot of all of this is that it could still be quite a while before there is clarity on whether 'no deal' has been avoided, whether Article 50 will be extended, and for how long. One way or another, it still seems there is a growing risk that the Brexit saga goes to the wire.