The EU's chief Brexit negotiator Michel Barnier has the coronavirus, he announced on Thursday.

"I tested positive yesterday for Covid-19. I'm as well as I can be, strictly confined to my home," Barnier, 69, said in a video posted on his Twitter account. "I'm fine, morale is good," added the former French foreign minister, who is in France. "I naturally am following all instructions, as does my team. My message to all those who are affected or currently isolated: we will get through this together!"

Barnier's revelation comes after the EU and Britain on Monday cancelled this week's post-Brexit trade talks because of the coronavirus outbreak. Officials had been discussing plans for a videoconference instead of face-to-face talks in London. 

Britain left the European Union on January 31 but both sides agreed a transition until the end of 2020 to allow them to negotiate a new partnership. Brussels had already warned that the timetable was too tight and delays from coronavirus have sparked calls in London for Prime Minister Boris Johnson to ask for more time.

This would be a major setback for the British government, which has promised to fully leave the EU by the end of the year come what may. The EU has published a draft of its intentions for the talks that has exposed deep divisions between the two sides.

The proposal would ensure Britain does not diverge far from EU rules on state aid and environmental, labour and quality standards. But Johnson's government says it wants a simple free trade agreement between "sovereign equals" and is prepared to sacrifice access to the EU market in exchange for the freedom to write its own laws.