One of the European Union negotiators working on a post-Brexit trade deal has tested positive for coronavirus, leading to a suspension in the talks.
The two sides have been meeting in Brussels with time running out to reach a deal before the Brexit transition arrangements expire at the end of the year.
The EU’s lead negotiator Michel Barnier said a member of his team tested positive.
Mr Barnier and his UK counterpart Lord Frost have been taking part in an intensified negotiating process in an effort to reach a deal which can be ratified by the end of the year, and any further delays could complicate matters.
Mr Barnier said that, together with Lord Frost, “we have decided to suspend the negotiations at our level for a short period”.
“The teams will continue their work in full respect of guidelines,” he added.
Lord Frost said he was in “close contact” with Mr Barnier about the situation.
“The health of our teams comes first,” he said and thanked the European Commission for their help and support.
UK officials in Brussels are working with the EU to discuss what will happen next.
It was unclear whether members of the negotiating team will have to self-isolate.
A UK Government spokesman said: “With respect to the relevant public health guidance, the UK and EU teams have agreed to continue to negotiate remotely for the time being.
“The talks will resume in person when it is judged safe to do so. The health and welfare of our staff are our priority.
“The negotiations have been conducted throughout in a way that is consistent with applicable social distancing laws and guidance.”
It is understood that no member of the UK team has been required to self-isolate and that talks are expected to resume in London when it is considered safe to do so.
European Commission president Ursula von der Leyen wished the member of the EU negotiating team a “speedy recovery” and said work would continue “in full respect of” Covid-19 rules.
The unwanted development comes with the negotiations at a crucial point.
The need for any deal to be approved by the European Parliament and member states means there is very little time left for negotiations.
The major issues in the talks remain access to UK fishing waters, the “level playing field” designed to prevent unfair competition on issues including state subsidies and the governance arrangements for any agreement.
Going into this round of negotiations in Brussels Lord Frost said there had been “some progress in a positive direction in recent days” but “we may not succeed” in reaching a deal.
It is not the first time coronavirus has disrupted the talks.
In March, Mr Barnier contracted coronavirus while Lord Frost also self-isolated after developing symptoms.
There was better news in the UK’s negotiations for a trade deal with Canada as Downing Street said talks were at an “advanced stage” and “progressing well”.
The EU has a deal with Canada and the UK is seeking to continue similar arrangements from January 1.
Canadian Prime Minister Justin Trudeau last week suggested the two sides were struggling to reach an agreement because British negotiators were out of practice, but Boris Johnson’s official spokesman told a briefing for Westminster journalists on Thursday morning that talks were progressing.
He said: “We are committed to securing a continuity trade deal with Canada before the end of the transition period.”