The topsy turvy trade talks between the U.K. and the European Union took another somersault on Sunday when Boris Johnson and Ursula von der Leyen gave negotiators another shot at closing a deal.

After the British prime minister and the European Commission president agreed in a phone conversation on Sunday to go the "extra mile,” officials involved in the process said an agreement could finally be struck this week, with just days to spare before the U.K. leaves the EU single market and customs union.

Forty-eight hours of intense diplomacy injected fresh momentum into a process that had seemed to be reaching the end of the road. The two leaders had set Sunday as the deadline to decide whether to call off their discussions.