BRUSSELS (Reuters) - The EU’s Brexit negotiator urged the British government on Saturday to stop playing “hide and seek” over its aims for trade ties and warned that delays in agreeing on judicial oversight risk wrecking any Brexit deal.

FILE PHOTO: European Union's chief Brexit negotiator Michel Barnier attends an EU's General Affairs Council in Brussels, Belgium, May 14, 2018. REUTERS/Francois Lenoir/File Photo

In pointed remarks after an ill-tempered week of talks in Brussels, Michel Barnier insisted he would not be intimidated by what he called a “blame game” from London of accusing the EU of inflexibility in rejecting British demands for close cooperation on security, trade and other issues after Brexit.

In the text of a speech in Portugal to experts in EU law, he accused British leaders of failing to understand that it was the unique legal structures of the EU, to which Britain had contributed for 45 years, which underpinned trust among member states. These, he said, could not be extended to a non-member.

The former French minister’s comments come two days after an EU official dismissed as “fantasy” London’s ideas for a customs deal, the border with Ireland and other issues.

British ministers said those remarks were not “helpful”. Both sides are hoping to make progress on a treaty before Prime Minister Theresa May meets the other 27 EU national leaders in a month in Brussels. They aim to agree a treaty by October.

Barnier said he was ready to have “political level” talks to try to advance in three key areas where uncertainty remains, 10 months before Britain is due to leave in March 2019 -- how to rule on future disputes over the withdrawal treaty, a “backstop” solution for the Irish border and a framework for future ties.

May’s government, deeply divided over how to stick close to the EU, is debating whether to drop its rejection of a customs union. Barnier said: “If the United Kingdom would like to change its own red lines, it must tell us. The sooner the better ... A negotiation cannot be a game of hide and seek.”

GOVERNANCE URGENCY

On the issue of the governance of a withdrawal treaty, he repeated the EU’s insistence that primacy of the European Court of Justice inside the Union be maintained in regulating any dispute that could not be resolved by a joint committee appointed by the political leadership of both sides.

The role of British judges would be respected, he added.

But “without an agreement on governance, there will be no withdrawal agreement and so no transition period.”

A British government spokesman said London had been clear that when Britain left the EU, it would leave the ECJ’s jurisdiction.

“We are working constructively to negotiate an approach to enforcement and dispute resolution which meets the key objectives of both the UK and the EU, underpinning the deep and special partnership we seek,” he said.

“However, we are clear the dispute resolution mechanism must respect the autonomy and integrity of both the UK and the EU: it will be for our courts to interpret and apply the agreement.”

Many businesses are counting on a broad status quo between Britain and the EU after Brexit, agreed until the end of 2020.

Barnier also criticized British officials for accusing the EU of inflexibility that would leave gaps in cooperation on security and other areas which would hurt both sides: “I see the temptation of a ‘blame game’ by which the European Union is responsible for the negative consequences of Brexit,” he said.

“But that will not sway us. That will not sway me.”

Citing British demands to be allowed to stay inside the EU’s data protection system in the interests of EU business, Barnier said this was to miss the importance of the EU’s internal rules.

“Let’s be clear: Brexit is not and never will be in the interests of EU businesses,” he said. “It would not be in those businesses’ interests to abandon our autonomy of decisions.

“The United Kingdom must face up to the reality of the Union. It must also face the reality of Brexit ... It is one thing to be inside the Union and another to be on the outside.”