Dutch GP organisers are still battling to prepare Zandvoort for next year's sellout race.
Even before the 2020 deal with Formula 1 was struck, opposition groups were vowing to take legal measures to prevent or delay the event.
Construction is already underway to upgrade Zandvoort, but environmental groups have banded together to call a stop to those works until permits are granted.
Local authorities acknowledge that permits are not yet granted, but the installation of dune screens to control the movement of frogs is already taking place.
"Circuit Park Zandvoort is ignoring regulations and procedures," the environmental groups wrote in a letter to authorities.
According to Dutch business broadcaster RTL Z, a judge will rule on October 27 whether construction needs to be temporarily halted at the circuit.
The most serious works are scheduled to begin in November.
