LONDON (AP) – Ireland´s prime minister has warned Britain that Brexit is far from finished — and the European Union will have the upper hand in upcoming negotiations on future relations between the two sides.

The U.K. is due to leave the EU on Friday, the first nation in the bloc to do so. It then enters an 11-month transition period in which Britain will continue to follow the bloc´s rules while the two sides work out new deals on trade, security and other areas.

Irish Prime Minister Leo Varadkar said Monday that “the European Union is a union of 27 member states. The U.K. is only one country.”

“And we have a population and a market of 450 million people. The U.K., it’s about 60 (million),” he told the BBC. “So if these were two teams up against each other playing football, who do you think has the stronger team?

“I always say we’re only at halftime on Brexit, it’s not done yet,” Varadkar added, ahead of a meeting in Dublin with the EU´s chief Brexit negotiator, Michel Barnier.

British Prime Minister Boris Johnson is adamant that he won´t agree to extend the Brexit transition beyond the end of 2020, even if a deal has not been struck.

Varadkar, however, said it would be difficult to secure a comprehensive agreement in time and there was a chance a deal might need to be approved by parliaments in all 27 EU countries — any of which could hold it up.

“We need to get down to business very quickly trying to get that trade deal, which is absolutely essential for the Irish economy, as well as of course for Britain’s as well,” said Varadkar, who is battling to retain his job in an election on Feb. 8.

Ireland is the only EU country to share a land border with the U.K., and Britain is one of Ireland´s top trading partners.