FILE PHOTO: European Union's chief Brexit negotiator Michel Barnier addresses the plenary of the European Parliament on Britain's withdrawal from the European Union during a debate on Brexit at the European Parliament in Strasbourg, France, September 18, 2019. REUTERS/Vincent Kessler

BRUSSELS (Reuters) - Brexit negotiator Michel Barnier said on Friday that the European Union was “firmly united” in insisting on a legally operative fix for the Irish border after Brexit should the backstop be dropped to unlock a divorce deal with Britain.

Britain is due out in a month but the sides have not been able to agree terms of their unprecedented divorce with a spiraling political crisis in the United Kingdom clouding the fate of Brexit further.

“We need a legally operative solution in the Withdrawal Agreement to address the problems created by Brexit on island of Ireland,” Barnier said on Twitter.

“EU27 firmly united. We must avoid hard border, protect the Good Friday Agreement, all-island economy and integrity of Single Market... We continue to defend EU27 interests and values... We stand united.”