With 50 days remaining, here are some of the deadlines and events that will be coming up

With 50 days remaining until Britain is scheduled to leave the EU on 29 March, the two sides have agreed to continue exploring possible tweaks to the Brexit deal that might get it over the line in the House of Commons, while still respecting the EU27’s guidelines.

So far, neither looks set to budge. Meanwhile, the clock is ticking for Westminster, Brussels and businesses. Here are some of the key dates and deadlines as Brexit finally gets real.

8 February: possible export problems. From this week, freighters setting sail from UK ports with cargo for far-flung destinations such as Australia and New Zealand, a journey of about 50 days, risk arriving after Brexit day with – in the event of a no-deal Brexit – no idea of the trade rules that will be in place.

14 February: Brexit debate in the Commons. This is most likely to be a general debate following a prime ministerial statement, because Theresa May will almost certainly not have a revised deal by then. But amendments to the motion could lead to “indicative votes” on Brexit options or an extension of the two-year article 50 process, possibly via a relaunched Yvette Cooper-Nick Boles amendment setting a deadline for MPs to back the agreement.

14 February: first statutory instrument deadline. According to the Institute for Government, this is the final day on which about half the secondary legislation needed to import EU laws can be introduced, because parliament must be given 40 sitting days to object to it. EU-related SIs can be passed more quickly in “urgent circumstances”, but still need to be approved by both houses within a 28-day window.

17 February: more trade woes. From this date, ships setting sail for Japan from the UK and vice versa could arrive to find themselves in the middle of no-deal tariff mayhem.

20 February: international treaty ratification deadline. About 80 of roughly 100 international treaties with other countries remain to be ratified by parliament, a process that – barring “exceptional cases” – requires 21 sitting days.

28 February: self-imposed deadline agreed by May and the European commission president, Jean-Claude Juncker, to discuss progress made by the two sides towards a revised deal the prime minister can bring back to the Commons.

Early-mid March: second “meaningful vote”. The European Union (Withdrawal) Act 2018 obliges the British parliament to hold a vote on the withdrawal agreement before the European parliament has its say.

21-22 March: article 50 extension request? With barely a week to go before Brexit day, EU leaders gather for their annual spring summit. This is when some EU officials think the UK might ask for more time to conclude Brexit by requesting an extension to article 50. This would need to be agreed unanimously by the EU27 and there is no time limit for it to do so – it could happen very late.

By 28 March: UK ratification of extension? If Britain has asked for an extension and the EU27 has granted it, both houses of parliament must vote to allow the legally binding exit date of 29 March to be changed.

Mid-late March: UK ratification of deal. If MPs eventually back May’s deal without an article 50 extension, the government still has to get the bill through both houses. Primary legislation of this sort can be rushed through quickly, perhaps with controversial elements stripped out. But an avalanche of amendments could still make the 29 March departure date unattainable.

25-28 March: EU ratification. If there has been no extension, the European parliament’s second Strasbourg meeting would be the last chance for MEPs to vote through the withdrawal agreement to get it agreed before Brexit day. EU ambassadors would then have a few dozen hours to rubber-stamp the final deal.

29 March: Brexit day? Without an extension, the UK will formally leave the EU on 29 March at 11pm UK time (midnight in Brussels). EU officials think a last-minute plea for more time by the UK would be unlikely, as by this late hour, events would have their own momentum. Equally unlikely, they believe, is the possibility of Britain cancelling Brexit – although the European court of justice set no notice period when it ruled the UK could unilaterally revoke article 50, so in theory, the government could still make a U-turn even at this stage.

15-18 April: EU ratification following an extension. If the UK has been granted a short technical extension to complete the Brexit process, MEPs’ monthly plenary meeting in Strasbourg would be the final opportunity for the European parliament to ratify the agreement before European elections.

23-26 May: European elections. If the UK sought and obtained an extension to article 50 that went beyond 2 July – the first day of the new parliament – it would have to take part in those elections, EU officials have said.