The British Athletics Indoor Championships, due to be in Glasgow in February, has been cancelled.
The event was to be at Emirates Arena for the second year running and was to serve as trials for both the European and World Indoor Championships.
But British Athletics have cancelled the event "to ensure the safety of all those due to participate".
It says that testing all those involved for Covid-19 would "not sufficiently mitigate the risks".
"British Athletics recognises our wider social responsibility to reduce Covid-19 transmission and to not overburden the NHS," a statement read.
"The logistics of safely staging a national championships comprising approximately 500+ attendees need to be balanced with the risks to those involved, the local community, and the medical climate."
British Athletics is exploring how it can stage an event to enable competitors to achieve qualification for the European Indoor Championships, scheduled to take place in Poland in March.
British 400m runner Zoey Clark described the news as "not altogether unsurprising".
"They have been saying it is going to go ahead for a while but there has been a lot of doubt in our minds as to whether they can host it safely," she said.
"It is so disappointing for everyone who has gone so long without races we were really looking forward to having this one."