V8 Supercars is reportedly threatening to quit the Australian Formula One Grand Prix if its support races aren't upgraded to championship status.
According to Fairfax Media, when V8's existing Melbourne deal ends in 2018, it won't renew its annual appearance on the F1 undercard unless the races are part of the title series.
"I can't see us there in 2019 unless it's a championship round," V8 Supercars chief executive James Warburton told Fairfax.
"Obviously, we'll fulfil our contract which runs through to 2018 but, beyond that, I can't see us racing there unless it's a championship round."
The Australian Grand Prix Corporation (AGPC) maintains there are ongoing efforts to gain F1 approval for the V8s to compete for championship points at Albert Park.
"It's a continuing effort," AGPC chief executive Andrew Westacott said. "Once again, contractual complexities got in the way, so we weren't able to achieve it for this year, but we're continually open and optimistic for the future."
The V8s have been the main supporting act at the Melbourne GP for all but one year since the F1 event moved from Adelaide in 1996.
But the races have never counted towards the V8 championship because of conflicting broadcasting deals and logistical impediments.