Theresa May just quietly made a sinister deal about EU citizens which puts us on the fast track to a bad Brexit

It’s like May is making it all up as she goes along, as if she never thought ahead to actually having to deliver on the details of what 'Brexit means Brexit' is about

After dragging her leopard print shoes for too long, Theresa May has finally made public her plans for “safeguarding the position of EU citizens living in the UK” – and it raises far more questions than it answers.

For example, will the UK guarantee the rights of all EU nationals already here? The answer is we don’t know because May hasn’t said. It all boils down to technicalities that only lawyers can appreciate. Not the way to win public confidence at a crucial time on such a fundamental issue.

Only those here during an as-yet-unspecified qualifying period will count. This will range from 29 May 2017 to 29 May 2019 – and it raises the possibility of the UK Government retrospectively stripping EU nationals of their existing rights. Not everyone who should be safe is safe. This won’t be decided later – perhaps two years from now. But we do know that Irish citizens will be unaffected thanks to an agreement forged in the 1940s. Confused? It gets worse.

If we knew the cut-off point for qualifying – which we don’t – would all EU nationals here at that time be allowed to stay? The answer is probably not. May is only considering qualifying EU nationals (not all EU nationals) currently here. Some out of work or in study will require proof of comprehensive health insurance to have residency in the UK as an EU national.

While many speak of free movement, there are restrictions like this to ensure migrants are not a burden on public services – and the UK Government is not very good at checking to see if every EU national in the UK is properly exercising their free movement rights. Many don’t find out they’ve not followed the rules correctly until it is almost too late and they’re having their application for residency rejected. They will be some of the EU citizens who may be forced to exit in 2019.

Any EU citizen not here for five years on Brexit day will have up to two years to acquire – and pay – for temporary residency. But no one knows when this is or how much this will be.

The questions don’t stop there. Theresa May told the House of Commons that the new rules won’t split up any families. But how can she know this when we don’t know who qualifies to stay and who doesn’t?

Not all spouses will meet May’s test. If a non-EU spouse joins his EU spouse in the UK and they break up within five years, what will happen to them both and their children? Would it matter if the children were born and bred in Britain?

We’re told that the Government “will tailor the eligibility criteria”, but not what the new criteria is likely to be. The Government provides an illustration showing for many arriving after the unknown cut-off date will face future immigration controls described as “depends on rules in place at the time” – in other words, the Government doesn’t seem to have a firm grasp of where it is going.

So is this about treating EU nationals like non-EU citizens? Not quite. There’s no requirement to pass an English exam or a citizenship test, but these will be required for temporary residents post-Brexit who want to stay permanently. In other words, it’s a complicated maze that doesn’t quite simplify the rules to make them knowable to anyone but the lawyers – and even they will be wading through the new regulations, if agreed, wondering at times what to do next.

EU nationals here and UK citizens abroad need certainty about their rights to work, live or study wherever they are currently in the UK. Instead of providing certainty and stability, Theresa May is serving up caveats and creating chaos.

And it will probably get worse. A key sticking point is the jurisdiction of the European Court of Justice. If there is some dispute about the enjoyment of residency rights by a EU national in the UK, which body should have a say?

The EU has made clear it may be unwilling to compromise on the ECJ – and the PM has said only British courts should have a say. Both sides seem quiet on whether they would be willing to agree some kind of international tribunal with representation from each side but chaired by some third party – but how exactly such a body would work is not yet even up for discussion.

It’s like May is making it all up as she goes along, as if she never thought ahead to actually having to deliver on the details of what “Brexit means Brexit” is about. This is no way to run negotiations and it makes for a fast path to a bad deal – at a huge cost to the country and our global reputation.

Thom Brooks is Head of Durham Law School and author of 'Becoming British: UK Citizenship Examined' (Biteback 2016) and tweets @thom_brooks