The EU27 agreed at a meeting of ambassadors in Brussels to a Brexit extension until January 31.

The official decision must be taken by EU leaders but that will be done by so-called "written procedure," which is now a formality and is expected to be launched Tuesday and take around 24 hours.

Although Prime Minister Boris Johnson and EU leaders earlier this month agreed a draft deal setting out the terms of the U.K."s exit from the EU, that deal has not yet been approved by lawmakers. Monday"s decision means the U.K. cannot now exit the European Union with no agreement legally in place on October 31 — the deadline set by the previous extension — something the EU27 and many in the U.K. were keen to avoid.

During the extension period, the U.K. will have to appoint a European commissioner as it "will remain a member state until the new withdrawal date, with full rights and obligations," the text states.