The disruption of the Swiss president’s National Day speech on Monday by hundreds of rightwing extremists has put the future of the event in question.
About 700 militants - twice as many as in 2004 - heckled Samuel Schmid during his speech on the Rütli meadow, known as the cradle of Switzerland.
Rightwing groups accounted for more than a third of all those in attendance at the Swiss National Day celebrations on the meadow and dominated proceedings by booing Schmid, calling him a "traitor".
Schmid responded by reminding the crowd that it was the duty of everyone to reject all forms of anti-Semitism, racism and extremism.
"What happened on Monday was unworthy," said Judith Stamm, president of the event’s organising committee.
Stamm said the authorities would consider all options to help prevent a repeat of the incident, including discontinuing the event.
Open to public?
She said the committee would not tolerate such a disturbance in future, but added she still believed the celebration should be open to the public.
The director of the committee, Herbert Ammann, said the organisers would also discuss turning it into an invitation-only event.
It was the tenth year in a row that rightwing extremists have made the journey to the meadow on the shores of Lake Lucerne, and their numbers have increased each year.
But there are only about 1,000 such militants in the country, and they are not well organised, according to the latest federal police report.
According to legend, representatives of the three founding Swiss cantons met on the Rütli in 1291 to form an alliance against the Habsburgs, their feudal lords.
swissinfo with agencies
The Federal Police say there are about 1,000 rightwing extremists in Switzerland.
According to one militant group, the protest was organised by the rightwing Party of Nationally Oriented Swiss (PNOS).
A PNOS member was elected to the town council in Günsberg in canton Solothurn in April.
Four PNOS members were found guilty of racism earlier this month.