That the EU27 has shown extraordinary patience with the UK throughout the Brexit talks is something of an understatement. But that patience, finally, appears to be coming to an end.

Although EU partners have always been in a stronger negotiating position, they have never sought to “punish” the UK – contrary to a popular narrative pushed by Brexiters. They’ve simply tried to maintain that Brexit takes place in an orderly fashion. That task has not been made easier by the May government’s persistent lack of clarity on (or perhaps comprehension of) the consequences of its negotiating position.

With days to go before the formal departure date of 29 March the Prime Minister has finally bent to the inevitable and earlier this week formally requested a three-month extension of the Article 50 deadline. The EU27 is clearly sympathetic to some sort of short extension if they feel that Mrs May can ultimately secure parliamentary adoption of her twice-rejected deal. And even a vote itself is doubtful unless the Speaker of the House of Commons, John Bercow, allows it to be put to MPs for a third time or the Prime Minister succeeds in circumventing his ruling.

But trust as well as patience on the EU27 side are rapidly disappearing. Early indications point to their agreeing a short extension until 23 May (the day of the European Parliament elections), by which date – if the May deal gets through the House of Commons – the UK will have left the EU and therefore under no obligation to fight those European elections. The 30 June date requested by May appears quite out of the question not least because in the intervening period the UK could arguably revoke its Article 50 notification but would not have representation in the European Parliament: a nightmare for the EU with potentially huge legal uncertainty and confusion.

Whatever the views of key players on the EU side who have made no secret not just of their sadness about the referendum result but also their (now vanishing) hope that the UK might somehow reconsider its decision of 2016, they are as alarmed as the UK government is about the prospect of a no-deal Brexit and, by and large, take the view that the withdrawal agreement thrashed out over almost two years is a good deal for them.

If, however, they do not believe the Prime Minister can get her deal through the UK Parliament in the coming weeks (presumably with the accompanying implementing legislation) then they are more likely to be minded to agree to a much longer extension of several months. Until quite recently that lengthier extension would have been granted with few if any formal conditions attached (partially for fear of being seen to meddle in UK domestic affairs) but the EU27’s now widespread exasperation has changed that. Prominent EU players are now openly saying that the UK has to show a major change of direction – be it a general election, second referendum, or even a dropping of key red lines – if this extension is to be agreed.

Given the volatility of British politics at the moment, the EU27 might well be wary of formally signing off their final position at the 21 March European Council meeting, instead preferring to confirm their agreement in principle to some kind of extension (to avoid chaos after 29 March) and leaving the details either to be announced at an emergency summit next week or through a simple exchange of letters.

If Brexit does happen, whatever form it takes and over whatever timescale, the UK and the EU are going to be locked into negotiations on their future relationship for years to come. With all the focus on Article 50, many seem to have forgotten that  the act of “Brexiting” is by no means the end of the UK’s divorce from the EU; it’s actually the start of a much lengthier and more complicated Phase 2 in the negotiations which will involve hammering out the details of what the UK’s and EU’s new trade relationship will be.

In those new talks the UK cannot continue to act in the way it has done until now. Leaving the EU will mean there’s no longer a seat at the table – at the Council, the European Commission, the European Parliament and at most regulatory agencies. Once an outsider the UK will have to devote enormous new resources not just to exert influence and shape policy, but also to acquire information and intelligence on what is going on in all these political and policy making fora.

Ironically, the UK government, rather than “breaking free of Brussels”, is realising that it will have to spend significant capital in the EU’s capital. It will be substantially increasing its workforce at the presumably renamed “UK Mission to the European Union”, but will also be reaching out to other players – businesses, civil society, think tanks and the like – in an attempt at the very least to keep up with developments, never mind being ahead of the game.

This should not just be a question of throwing additional resources at information-gathering strategies: it has to be part of a properly planned post-Brexit public diplomacy strategy. The UK has an enormous amount of fence-mending and bridge-building to do in this area. And since even now the ultimate outcome of Brexit is unknown, this new strategy should still be pursued even if the UK ends up remaining in the EU.

Paul Adamson is the Editor of E!Sharp and a Visiting Professor at the Policy Institute, King's College London.