The Circuit de Barcelona-Catalunya, home of the Spanish Grand Prix, is facing a reduction in its funding from the city council.
The circuit receives in the region of €4 million annually for holding Formula 1 races, but that figure is set to be cut to €2 million this year.
Barcelona elected a new council in May last year, just two weeks after officials at the circuit signed a new deal to keep Formula 1 until at least 2019.
The Barcelona-in-Common party were elected and have opted to prioritise other areas of the city, having already warned the circuit mid-2015 that its subsidy would be reduced.
First Deputy Mayor Gerardo Pisarello confirmed that the funding is being gradually reduced in order to aid the circuit to become self-sufficient.
Barcelona has hosted the Spanish Grand Prix since the circuit was built in 1991.