Christian Ude said that Olympic supporters have to fight back against opponents of the bid from Garmisch-Partenkirchen, which is due to host Alpine skiing events in 2018. Around 50 protestors gathered near Munich’s media centre to air their feelings during the first day of the International Olympic Committee (IOC) evaluation commission visit on Tuesday.

Opponents of the bid have cited environmental concerns in attempting to force a referendum against the Olympics taking place in the region with such a move, if successful, likely to bring a lengthy court battle. The IOC, which has already visited the Games’ other two candidate cities of Annecy in France and PyeongChang in South Korea, will vote on the host city on July 6 in Durban, South Africa.

“We have to do something and react,” Ude said, according to the Associated Press. “The other side just wants to have a sword hanging over the bid and we want to do something against it.” In addition to the threat of a referendum, several farmers in Garmisch-Partenkirchen have refused to cede land needed for some Olympic venues.

“Our plans would ensure the expansion and modernization of the Olympic Park and another 40 years of sustainable use,” said Ude. “This would deliver an unprecedented 80 years of sustainable Olympic legacy.”

Later today, the German bid will present a study to the IOC panel that will claim the Olympics would bring a positive economic impact of Eur3 billion to Munich.