Long-serving (and long-suffering) Brussels-watchers will be aware that the EU brings a slightly Alice in Wonderland approach to business. Things are concrete and certain, but simultaneously changeable and temporary – “black and white” guarantees can dissolve overnight, immovable legal principles can be disregarded when inconvenient, and hard deadlines can slip and slide when required.

So when I lay out below the timeline for what’s about to happen in the Brexit talks, readers should bear in mind that all this could be flipped on its head if it becomes convenient or necessary to do so. But anyway, here it is:

Monday 4th December – Morning: The Commission (in the person of Jean-Claude Juncker), the European Parliament (represented by Guy Verhofstadt) and Michel Barnier, the EU’s Brexit negotiator, meet to discuss the state of the talks. Verhofstadt is seeking assurances about the Parliament’s declared priorities, including EU citizens’ rights. Also this morning, the Irish cabinet is meeting to consider next steps on the question of the border.

Monday 4th December – Lunchtime: Theresa May meets Juncker and Barnier for a working lunch. Donald Tusk, the European Council’s President, described this as “the absolute deadline for Prime Minister May to improve her Brexit divorce offer or face failure”. The goal is to reach agreement in principle between the three that “sufficient progress”, those golden words, has been secured on the EU’s three “stage one” priorities – EU citizens, money, and the Northern Ireland border. Even if there is agreement in principle, such a verdict can’t be made official and thereby becoming meaningful until the wider institutions including the Council agree. If there is no agreement, then that “absolute deadline” could yet slide into a flurry of offer and counter-offer tonight and tomorrow – it’s notable that there is a gap of almost two days between this meeting and the next official step.

Wednesday 6th December – Morning: Barnier formally reports to the European Commission about the progress of the talks. Juncker will presumably then give his view to his colleagues, and the assembled Commissioners will discuss and come to an official verdict on whether the progress of talks is sufficient to proceed on to discussing trade and the future relationship.

Wednesday 6th December – Afternoon: Representatives of the remaining EU member states meet to discuss the Commission’s view on the talks, and to prepare for the forthcoming EU Council meeting. The official decision still will not have been taken, but the meeting might give some idea of where the different national governments stand on the question of progressing to the next stage – if they’re all discussing how such Stage Two talks would work, that’s a good sign, but if one or more are still objecting to advancing at all, then there’s trouble ahead.

Tuesday 12th December: The Europe ministers of the remaining EU member states meet in preparation for the forthcoming Council meeting. Like the discussions on the afternoon of the 6th, this won’t formally conclude the matter but could offer some insight into the state of play. If there were still issues to be worked out the week before, then this will be a moment to seek signs of movement that might have been produced by further discussion and consideration over the intervening weekend. It is at this stage that the agenda for the Council meeting is officially set.

Thursday 14th December: The European Council – the leaders of the member states – will meet as normal, with an agenda including defence, migration and social policy. Theresa May will be in attendance, so this is another opportunity to influence those around the table – be it through soft diplomacy or firmer policy offers on issues technically unrelated to Brexit. Despite Tusk’s ‘absolute deadline’, the reality is that the bartering process may well still be going on at this stage.

Friday 15th December: The Article 50 version of the European Council – all the members except May – meets at last to officially discuss and deliver a verdict on the progress of Stage One of the Brexit negotiations. There is no official definition of what ‘sufficient progress’ means – that was a deliberate decision, both to maintain agreement among the member states and to avoid disclosing too much of their negotiating strategy to the UK. Essentially, it’ll be a decision based on the politics and the feel of the situation as much as on any formal criteria. The EU loves to demonstrate a bit of tension and drama followed by a supposedly hard-won solution, apparently to make it all seem a more worthy process, so these meetings can and do go on into the early hours sometimes. We could get no agreement, or full agreement to proceed to the next stage, or a fudged semi-agreement of some sort – it’s all to play for in the next few days.