Brussels (AFP)

The European Union and Boris Johnson strongly opposed Tuesday Brexit, Brussels deeming insufficient a proposal by the British Prime Minister to prevent the return of a hard border on the island of Ireland, two months from the divorce.

The new Prime Minister has for the first time publicly addressed a letter to the EU Monday in which he details his arguments against the device of the "backstop", the safety net included in the withdrawal agreement, rejected three times by the Parliament British, and that he has continued to denounce.

But the response of the President of the European Council Donald Tusk, recipient of the mail, was scathing.

"The + backstop + is an insurance to avoid a hard border on the island of Ireland as long as an alternative is not found," said Tusk in a tweet.

"Those who are against + backstop + and who do not propose realistic alternatives are in fact in favor of reestablishing a border, even if they do not admit it," he retorted, without explicitly mentioning Boris. Johnson.

- "Impossible Solution" -

The two men must meet at the weekend at the G7 summit in Biarritz. Before this meeting, Johnson will meet with Chancellor Angela Merkel Wednesday in Berlin and with President Emmanuel Macron Thursday in Paris.

The European Commission has also condemned the London proposal, which mentions in more detail in its letter "alternative arrangements" instead of "backstop".

This European response provoked an equally sharp response from London.

If the withdrawal treaty "is not reopened and the backstop abolished, there is no possibility of agreement," said a spokesman for Downing Sreet.

"It has already been rejected three times (...) and this solution is simply impossible, as clearly stated in the Prime Minister's letter," he added.

The controversial device provides that, for lack of a better solution after a transitional period, and to avoid the return of a border between the British province of Northern Ireland and the Republic of Ireland, the United Kingdom all whole remains in a "single customs territory" with the EU.

It was designed both to preserve the 1998 peace agreements, which ended three decades of violence, and the integrity of the single European market.

- Jump in the void -

In her letter Theresa May's successor believes that this device is "undemocratic and undermines the sovereignty of the British state".

Moreover, it would prevent him from conducting a commercial policy independent of EU rules, he notes, while already Donald Trump dangles the promise of a "fantastic" deal after the divorce.

This letter "does not propose a legal operational solution to prevent the return of a hard border on the island of Ireland", criticized a Commission spokesperson, Natasha Bertaud.

"It does not specify what these alternative arrangements could be and even admits that there is no guarantee that they will be in place by the end of the transition period", by the end of 2020, did she noted.

Since the conclusion of the November 2018 divorce agreement between the EU and Theresa May, the EU has repeatedly stated that it will not be renegotiated.

After successive rejections by British MPs, who also opposed an exit without agreement, the date of Brexit, originally scheduled for March 29, 2019, was postponed to October 31 of the same year.

As of 1 September, London will cease to attend most EU meetings, except for "national interest" meetings.

Boris Johnson has repeatedly stated that with or without an agreement, the divorce would take place at the end of October, despite the heavy consequences announced, especially economic, of a brutal separation.

In his letter, the Prime Minister also said his preference for an exit with an agreement, "our highest priority", a commitment that did not fail to note Tuesday the European Commission, while the consequences of a jump in the void are also dreaded on the other side of the Channel.

© 2019 AFP