The departure of one of the companies based at a Birmingham leisure park has been called a setback by those fighting to secure the site's future.
Stock car race organiser Incarace has pulled out of Birmingham Wheels after failing to agree terms on a new lease.
Businesses there said they were told by the city council they had to leave by the end of January amid a rent row.
The council later overturned a plan to evict the eight tenants, but campaigners worry over what comes next.
The Save Birmingham Wheels group said the loss of Incarace was a "setback", although it would work to clear-up continuing uncertainty about the future.
It said it was looking to fill the gap the motorsport company left behind, and talks were ongoing to preserve the site's future as a leisure venue offering various racing opportunities.
The site, in Bordesley Green, which is owned by the local authority, has held sporting events for more than 40 years.
Councillors voted to evict tenants on the site following a row over rent arrears of more than £700,000 owed by the leaseholder Birmingham Wheels, which is itself a charitable company operated by the city council.
The eviction decision was then overturned, and while the site was earmarked for development, tenants were told they could stay on pending the outcome of lease negotiations.
But Deane Wood, managing director Incarace, said the company had failed to reach an agreement.
He said one of the reasons was that only a one-year term was available, with the possibility of a one-year extension.
He said the departure would cause issues with future fixtures and asked people to be patient until the situation was resolved.
A council spokesperson said: "The council said it would work with licensees of the Birmingham Wheels site to explore potential opportunities for activities to continue on alternative sites or on the Wheels site in the short-term, if a suitable agreement could be reached.
"As such, officers have met with the licensees' representatives and are continuing discussions."
It comes after a coroner called for urgent action at the site to prevent further deaths after sponsor Colin North, 60, was hit and killed by a recovery vehicle as he walked along a track to present trophies on 16 November.
Correction 20 February: This story has been amended to make clear that the site's future as a racing venue is yet to be decided.
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