Tottenham Hotspur announced the postponement of Thursday's Europa Conference League clash with Rennes following a severe coronavirus outbreak at the Premier League club, but their French opponents called into question the decision.

Tottenham boss Antonio Conte revealed on Wednesday that eight of his players and five members of staff had tested positive for Covid-19.

It had appeared UEFA would insist on the Rennes match going ahead in north London if Tottenham had the minimum number of 13 players available, but the rapid spread of the virus forced a change of plan.

"We can confirm that our UEFA Europa Conference League Group G home fixture against Stade Rennais will not take place tomorrow (Thursday 9 December at 8pm UK) after a number of positive Covid-19 cases at the club," a Tottenham statement said.

"Additionally...the club has been advised to close the first-team area of its training centre at this time, in the interests of the health and safety of players and staff.

"All other areas of the training centre remain operational."

The postponement left Rennes furious, with the French side saying they had been told by Tottenham the game would go ahead before boarding a flight to London.

"Tottenham did not want to announce the number of players with Covid when the rules stipulate a game must be played as long as a team has 13 outfield players and one goalkeeper," they complained in a statement.

"With the match not being officially postponed by UEFA, Stade Rennais have maintained the decision to play."

It has been reported that Tottenham are now considering asking for their Premier League match at Brighton on Sunday to be postponed.

After the Brighton game, Tottenham face top-flight fixtures against Leicester on December 16 and Liverpool on December 19.

Last season, Tottenham saw matches against Aston Villa and Fulham postponed due to Covid outbreaks within the opposition.

Tottenham manager Antonio Conte
Tottenham manager Antonio Conte AFP / Oli SCARFF

"I think that I haven't got to send a message to anyone because the situation is very clear," Conte said of the potential for more of his team's games to be postponed.

Conte admitted the sudden outbreak had left his squad scared.

"To speak about football today is impossible. The last situation made me very upset," he said.

"The situation is serious. There is a big infection. Again at the end of the session, one player (tested) positive, another staff (member) positive. Tomorrow, who (will it be)?

"Now, for sure, we are a bit scared because tomorrow we don't know what happens."

Conte was not able to confirm whether it was the new Omicron variant causing the outbreak, but revealed he had been vaccinated.

On Wednesday, British Prime Minister Boris Johnson announced a wave of measures aimed at slowing the spread of the Omicron variant.

"I think everyone takes (their own) best decision and it is a question for the medical department about people that whether they are vaccinated or not," he said when asked about the vaccination status of his players.

Conte was supposed to be joined by Spurs' Danish midfielder Pierre-Emile Hojbjerg at the pre-match press conference, but instead faced the media on his own.

"Every day we are having contact with the people that are false negative and become positive and then everyone is a bit scared, I think, because we all have family and why I have to take this risk?" Conte said.

"I think that it is not right for everyone because we have family and we have contact with them when we come back home.

The postponement gives UEFA a headache over the rescheduling of the game.

Rennes have won Group G, while Tottenham are level on points with third-placed Vitesse Arnhem.