Brexit Secretary David Davis insisted “we will not be paying 100 billion”.
Leaving the EU will not be quick or painless for Britain, the European Commission’s chief negotiator has warned as a row blew up over the size of the UK’s divorce bill.
Michel Barnier refused to be drawn on reports the Commission plans to hand Theresa May a bill of 100 billion euro (£84.5 billion), but said there must be a “settling of accounts”.
But Brexit Secretary David Davis insisted “we will not be paying 100 billion”.
He said, if Brussels failed to reach a deal acceptable to Britain, the UK would pay nothing.
The row came as Mr Barnier set out the Commission’s detailed negotiating guidelines for the first phase of withdrawal talks, expected to begin in earnest after the June 8 General Election.
The guidelines confirmed the Commission expects to safeguard the lifelong status and rights of EU citizens who settle in the UK right up to the date of withdrawal, as well as family members who join them following Brexit.
They assert the competence of the European Court of Justice in Luxembourg to protect those rights, even after the UK has left.
The UK will be expected to “close the account” in a “single financial settlement” which will cover not only commitments to fund the EU’s 2014-20 budget, but also programmes to support countries like Turkey and Ukraine.
Speaking in Brussels, Mr Barnier said: “Some have created the illusion that Brexit would have no material impact on our lives or that negotiations can be concluded quickly and painlessly. This is not the case.
“We need sound solutions, we need legal precision and this will take time.”
Mr Barnier said the first phase of negotiations will focus on the financial settlement, the status of expatriate citizens and the future border between the UK and EU in Ireland, and he hopes to be in a position by October or November to decide whether sufficient progress has been made to move on to talks about future trade relations.
In order to move to the second phase, the EU will need “clear commitments” which cannot be reopened, rather than “window dressing” from the UK, Mr Barnier stressed.
Mr Barnier denied Brussels was demanding a “blank cheque” from Britain and said the financial settlement was not a “punishment” for leaving.
The Commission’s calculation of Britain’s liabilities should be “incontestable” and there would be “explosive” consequences if it was not met, he said.
“This is not a punishment, nor is it an exit tax of some kind,” he said.
“The Union and the United Kingdom have mutual commitments. They have committed to financing projects and programmes together. We decided these programmes together.
“We benefit from them together, and we finance them together.
“Basically, we have to close the account, and it is no more and no less. No punishment. There is no Brexit bill.”
Mr Davis said he did not recognise the numbers being “bandied around” for the Brexit fee.
He insisted Theresa May would play a full part in the negotiations, dismissing as “laughable” reports Brussels would allow her to discuss Brexit only with Mr Barnier and not with leaders of the 27 remaining member states.
“We are not entering the negotiations as a supplicant,” he told a press conference in London.
“We will decide the structure of our negotiating team, not the EU.”