What No10’s legal advice says ... and what it actually means

How would the backstop work?

What it says: Attorney General Geoffrey Cox says in his legal advice that Northern Ireland stays in the EU customs union and the single market for goods and must accept European Court jurisdiction in these areas. There is a separate customs union between Great Britain and the EU – with Great Britain accepting EU tariff levels. Goods passing between the mainland and Ulster will require ‘declarations’ and would also face periodic regulatory checks.

What it means: Mr Cox spells out the full extent of the ‘wedge’ the backstop would drive between Great Britain and Northern Ireland, in order to preserve the an ‘open border’ with Ireland. While Britain would escape the writ of EU judges, Northern Ireland would not. The description of Great Britain as a ‘third country’ for goods going into Northern Ireland is a red rag to the Democratic Unionist Party.

Is the backstop indefinite?

What it says: ‘It is difficult to conclude other than the [backstop] is intended to subsist even when negotiations have clearly broken down,’ Mr Cox writes. ‘Despite statements… that it is not intended to be permanent, and the clear intention of the parties that it should be replaced by alternative, permanent arrangements, in international law the backstop would endure indefinitely until a superseding agreement took its place.’ What it means: This confirms what Mr Cox told the Commons, that once in the backstop, there is no obvious means of escape, and it will continue ‘indefinitely’ under international law, keeping the UK in a customs union with the EU. He also makes clear that the ‘review mechanism’ secured by Mrs May and the requirement of the EU to act in ‘good faith’ and use ‘best endeavours’ to negotiate a new agreement are unlikely to provide a smooth exit – so the politicians will have to find a solution.

Conclusion

What it says: Mr Cox says the backstop ‘does not provide for a mechanism that is likely to enable the UK lawfully to exit the UK wide customs union without a subsequent agreement… even if the parties are still negotiating many years later, and even if the talks have clearly broken down and there is no prospect of a future relationship agreement’. There is a ‘legal risk’ of ‘protracted and repeating rounds of negotiations’ but this must be weighed against the ‘political and economic imperative’ for both sides to do a deal.

What it means: As the Government’s chief lawyer, Mr Cox is making clear that in legal terms, there is no straightforward way out. But he is also a politician, and concludes that both sides are likely to want to find a ‘politically stable and permanent’ future relationship.