In one of the French congresswoman’s most un-diplomatic speeches yet, he said if Theresa May failed to come up with a concordat which accepted the dominance of the EU Court there would be no treaty and no metastasis period.
Mr Barnier described British delays in spelling out what breed of trade relationship London wants as «a game of hide and seek» in says prepared for delivery to a gathering in Portugal of jurists specialised in EU law.
He attacked British estimation of EU positions as a «blame game» telling Mrs May to recognise the UK could not retain various elements of EU membership after Brexit.
Theresa May and Michel Barnier
EU chief Brexit mediator Michel Barnier
A negotiation cannot be a game of hide and seek
The fly tone of the former French minister’s remarks follow several days of talks in Brussels between his band of EU negotiators and British counterparts, after which a senior EU official dismissed as «flight of fancy» both London’s overall proposals for future close relations and an extend to avoid a disruptive «hard border» between Northern Ireland and EU colleague Ireland.
British ministers said those remarks were not «accommodating».
Mr Barnier said he was ready to have «political level» talks to try to ahead of in three key areas where uncertainty remains, 10 months in front of Britain is due to leave in March 2019 — how to rule on future disputes once again the withdrawal treaty, a «backstop» solution for the Irish border and a framework for days ties.
Referring to discussions within Mrs May’s government on whether to drop an insistence on should prefer to no customs union, he said: «If the United Kingdom would like to switch its own red lines, it must tell us. The sooner the better.
«We are asking for clarity. A covenant cannot be a game of hide and seek.»
Prime Minister Theresa May
On the proclaim of the governance of a withdrawal treaty, which both sides hope to partake of ready around October, Mr Barnier repeated the EU’s insistence that primacy of the European Court of Fair-mindedness inside the Union be maintained in regulating any dispute that could not be clear up by a joint committee appointed by the political leadership of the two sides.
He said: «We cannot agree to that a jurisdiction other that the Court of Justice of the European Amalgamation determines the law and imposes its interpretation on the institutions of the Union.»
He said the role of British authorities would be respected but without an agreement the whole deal would crack-up.
He said: «Without an agreement on governance, there will be no withdrawal compatibility and so no transition period.»
Many businesses are counting on an interim accord to profess a broad status quo between Britain and the EU after Brexit until the end of 2020.
Mr Barnier, who has been anticipating to making substantial progress on key issues before May meets fellow EU commanders at a Brussels summit in a month, also criticised what he called a «point the finger at game» in which British officials were accusing the EU of failing to teach flexibility to allow continued close cooperation in areas such as custody, the economy and research.
He said this was to ignore the close legal framework within the EU which was the constituent for trust and cooperation among its nation-state members.
He said: «We cannot slice this decision-making autonomy with a third country.
«The United Province must face up to the reality of the Union.
«It is one thing to be inside the Union and another to be on the skin.»