The European Union has “formally adopted” a flexible extension to Brexit deadline until Jan. 31, 2020, European Council President Donald Tusk announced Tuesday.

“The EU27 has formally adopted the extension,” Tusk tweeted.

“It may be the last one,” he said, signaling there could be no more extension. He also appealed to Britain to “make the best use of this time.”

The extension was agreed on earlier this week by the 27 members of the union.

The U.K. was set to leave the EU on Oct. 31 but a new extension granted by the bloc has furthered the deadline to

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