The Circuit of Wales has denied it failed to meet the funding arrangements for Donington to host this year's British round of MotoGP.
On Tuesday, Donington issued a statement saying it was breaking off its partnership with CoW after the Welsh circuit had failed to meet its part of the agreement.
Donington was scheduled to host the MotoGP event this year while a new circuit was built in Wales for the 2016 race.
The construction, however, has been delayed.
But the Circuit of Wales claimed later on Tuesday that the deal was broken off because it refused to meet Donington's demands to pay for the necessary track upgrades to host the race.
CoW said it was still committed to having a British round of the series this year.
"We are unwilling to provide the significant funding that DPRL required for the necessary track upgrades."
"The Circuit of Wales is disappointed to have been unable to reach a contractual agreement with Donington Park Racing Limited (DPRL) to host the British round of the 2015 Motorcycle Grand Prix World Championship," it said in a statement.
"Contrary to claims by DPRL that the Circuit of Wales is unable to meet the funding arrangements, we are unwilling to provide the significant funding that DPRL required for the necessary track upgrades to host the British Grand Prix without a signed contractual agreement.
"We have all of the funding necessary in place to promote and host the 2015 race in the UK.
"All funding for the flagship Circuit of Wales regeneration development in Blaenau Gwent is on track with works due to start later this year following the outcome of the public inquiry in March.
"The Circuit of Wales will continue to promote the British round of the FIM MotoGP World Championship and is fully committed to delivering the event later this year. "