The last minute-bid by Barnier comes just days before British Parliament is due to vote on a withdrawal deal agreed between the two sides
The EU's chief Brexit negotiator Michel Barnier on Friday proposed that Britain could leave the bloc's customs union after the divorce though the offer would not include Northern Ireland which will anger London. Barnier's proposal "aims to counter arguments from the British who say they want to trap the UK in a customs union", a European diplomat told news agency AFP. But it risks "making Theresa May very angry", he added, because it goes back to an earlier version of the "backstop", limited to Northern Ireland, which May insisted the EU abandon.
The last minute-bid by Barnier comes just days before British Parliament is due to vote on a withdrawal deal agreed between the two sides, in which the fate of the Irish border is seen as a key issue.
"The EU commits to give UK the option to exit the single customs territory unilaterally," Barnier said on Twitter after a meeting with the ambassadors of the remaining 27 EU states.
However, "the other elements of the backstop must be maintained to avoid a hard border," said Barnier, in reference to alignment between Northern Ireland and the EU-member republic.
Both the EU and Great Britain want to prevent a "hard border" that would bring controls between the British province of Northern Ireland and EU-member Ireland after the Brexit.
Earlier, British Prime Minister Theresa May insisted that Britain will leave the European Union on schedule next month, amid signs that her promise to give Parliament a vote on delaying Brexit was boosting support for her unpopular EU divorce deal. May has bowed to pressure from within her Conservative government and given Parliament the chance to delay Britain's scheduled March 29 departure if lawmakers fail to approve her divorce agreement with the bloc.
Without a solution in a future arrangement, the current deal agrees to keep the UK in a customs union with the EU until a better answer can be found.
But supporters of Brexit fear that Britain would then be trapped permanently in the EU, and have refused to back the deal.
The counter-offer will almost certainly be refused or ignored by the government of Prime Minister Theresa May, which depends on unionist MPs from Northern Ireland for its majority.
Putting a post-Brexit border in the Irish Sea is a strong red line that May's government has refused to concede.