Preparations for the 2020 Dutch GP are on schedule, race spokesman and former F1 driver Jan Lammers insists.

Recently, environmental opposition groups have been campaigning legally and bureaucratically against Zandvoort's efforts to upgrade the circuit for F1.

But so far, the legal challenges have been overcome and Zandvoort now possesses the permits it needs for the most significant construction works.

"That didn't surprise us," Lammers told the Dutch publication Formule 1.

"Many people think no grand prix is more sustainable than a grand prix. But without the race, we would not have had these discussions and changes.

"Look at the new train station," Lammers continued. "It should have been there 20 years ago, and without Formula 1 it would not have happened even now.

"The new station will be good for Formula 1, but for the other 362 days of the year it will also benefit Zandvoort," he added.

So amid reports that delayed construction works on a tight schedule had put Zandvoort's preparations perilously behind, Lammers insisted: "So far, everything is going according to schedule.

"All the noise that you hear is just about doing business in the year 2019."