The EU’s chief negotiator, Michel Barnier, was forced to go into self-isolation and face-to-face Brexit talks in Brussels have been suspended after a member of the bloc’s negotiating team tested positive for coronavirus. In a development that will put further pressure on the tight timeline for a successful outcome in the trade and security talks, Barnier shut down the talks in the Belgian capital with the agreement of his British counterpart, David Frost. The two sides had been aiming to strike an agreement by next week to allow time for the European parliament to ratify any potential deal, with a possible emergency sitting on 28 December pencilled in. In an attempt to keep to that tight deadline, the two sides said video conference negotiations would continue but British officials are expected to leave Brussels on Friday. The talks were also suspended in March when Barnier and Frost contracted the virus. It is understood that none of the 50 UK officials in Brussels will need to quarantine as they were not in close contact with the EU official. Barnier’s team has been more affected by the development. Under Belgian law, anyone testing positive should quarantine for seven days while those who have had contact with an infected person must stay in isolation for 10 days. The EU’s chief negotiator tweeted: “One of the negotiators in my team has tested positive for Covid-19. With David 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.” It is understood Barnier will ask a commission official outside his senior team to brief EU ambassadors in person on Friday morning about the latest twists and turns in the negotiations. Shortly after Barnier’s announcement, Frost also issued a short statement. He tweeted: “I am in close contact with Michel Barnier about the situation. The health of our teams comes first. I would like to thank the European commission for their immediate help and support.” The negotiation is on a knife-edge, prompting the French president, Emmanuel Macron, to call on the European commission to ramp up no-deal preparations to prepare businesses for the worst. The UK and EU teams have been locked in talks in Brussels since Monday. In six weeks the UK’s transition period will end and it will leave the EU’s single market and customs union. 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.”