On the Brussels side, leaders have also been clear about the EU’s red lines – any rights must be balanced by obligations and a third country cannot enjoy the benefits of membership.
They have also expressed doubts that it will be possible to reach an agreement covering all the areas where the UK says it wants to negotiate before December 2020.
The short time frame will compel the EU27, who themselves have differing priorities, to agree the issues on which agreement has to be found. However, efforts on the EU side to impose sequencing are likely to be resisted by London.
There are many other potential minefields.
The negotiations will cover a range of sensitive substantive issues – fish, data protection, intellectual property, energy, transport – and procedural questions such as the role of joint committees, where the UK and the EU are unlikely to see eye-to-eye.
And the mood music will be affected by how the UK is seen to be treating EU citizens in the UK under the settled status scheme.
A no trade deal outcome is a possibility in December 2020. But unlike leaving with no Withdrawal Agreement, citizens’ rights, Ireland and the financial settlement would be settled – and the less close a relationship the Johnson government seeks, the less difference not having a deal in place would make.