Badminton's showpiece Thomas and Uber Cup was postponed Tuesday after a string of countries and regions withdrew over coronavirus fears, officials said, in a major blow to the sport's restart.

The men's and women's world team championships had been set to take place in Denmark next month, and would have been the first ­international tournament since the pandemic halted badminton in March.

But the Badminton World Federation (BWF) said it had taken the "tough decision" to delay the event as the pullouts meant they were not able to deliver a high enough level of competition. No new dates were announced for the tournament, which has now been postponed three times, but the BWF said it wouldn't take place before 2021.

A further delay to the tournament, which had been scheduled to take place in Aarhus from October 3 to 11, had started to look inevitable in recent days after some of Asia's top talent withdrew.

Indonesia, who are 13-time Thomas Cup champions, as well as Chinese Taipei, Thailand, South Korea and Australia had all decided to skip the event.

Leading Indian player Saina Nehwal, who had been due to play in the women's Uber Cup, had questioned whether pushing ahead was a good idea, while the Olympic Council of Malaysia had also called for a postponement.  

The delay is a major setback to efforts to resume international competition, as it was the biggest event left on the calendar this year after the Olympics were postponed.

It also means that players face a packed calendar next year, potentially with four major tournaments. 

If the Thomas and Uber Cup goes ahead in 2021, it could take place in the same year as the Olympics, the world championships and the Sudirman Cup.