UK Athletics is planning to take legal action after this year's Anniversary Games were moved out of London, a decision that the governing body's chief executive said tarnishes the legacy of the 2012 London Olympics.
West Ham United's London Stadium was due to host the Diamond League meeting on July 13, but the London Legacy Development Corporation this week said the event would have to be staged in Gateshead or Manchester as the cost required to convert the football stadium to an athletics venue and back was too much.
Gateshead is already staging the first meeting of the 2021 Diamond League season on May 23 after the event was moved out of Rabat, while Manchester is set to hold the British Championships in June.
"We're just not going to walk away," UK Athletics chief executive said Joanna Coates to the Guardian.
"It's outrageous the way they've treated us. Hosting a major event each year in London was a major legacy of the 2012 Olympics, so to seek to trash it is unbelievable.
"It is devastating for us and our athletes, many of whom will be days away from going to compete on the biggest stage of their lives. We believe the LLDC are categorically in breach of their contracts and we are going to fight all the way."
Coates said UK Athletics was planning to stage several events in the lead up to the Diamond League meeting to allow British athletes to hit top gear ahead of the Olympics.
"We have to give those athletes the best possible opportunity to perform, because the public will not want to see us fail in Tokyo," she said.
The LLDC said the decision was taken as the Diamond League meeting was the only event scheduled to take place at the venue.
"For the stadium, and ultimately taxpayer, to face costs of around £3 million to prepare for one evening of athletics rather than the full summer calendar... seems disproportionate in these extraordinary times," a spokesperson for the LLDC said.