The EU and UK have reached a post-Brexit trade deal, agreed a zero tariff-free trade deal, British Prime Minister Boris Johnson announced today via Twitter.

Once ratified by both sides, the agreement will ensure Britain and the 27-nation bloc can continue to trade in goods without tariffs or quotas after the U.K. breaks fully free of the EU on Jan. 1.

The announcement followed a final call between Boris Johnson in Downing Street and the European commission president, Ursula von der Leyen, in her Berlaymont headquarters in Brussels – at least the fifth such call over the last 24 hours.

As the deal was announced, Mr Johnson – who had repeatedly said the UK would “prosper mightily” without a deal – tweeted a picture of himself smiling with both thumbs lifted in the air.