The oldest paper version of the Swiss Federal Charter is due to go abroad for the first time but a group of conservative citizens are trying to keep it at home.
Politicians from the rightwing Swiss People's Party said they want to buy the 700-year old document to prevent it from being taken to the United States for an exhibition on Americans with Swiss roots.
The group, led by People's Party parliamentarian Christoph Mörgeli, said on Tuesday they were willing to help raise SFr1 million ($760,000) to acquire the Federal Charter.
The aim of the foundation, made up of several politicians and other unnamed citizens, is to ensure that what they call " a cornerstone of Swiss civilisation" will never leave the country.
They also criticised the fact that the historic document is insured for only SFr1 million, saying this shows the Swiss authorities don't take the country's cultural heritage seriously at all.
The cantonal government of Schwyz where the Federal Charter is permanently on show rejected the offer of the group, saying the document was not for sale.
Officials said the authorities had carefully examined all aspects and the curator for the Charter Museum said the document would not be at risk during its journey.
Interior minister Pascal Couchepin for his part told parliament on Monday that the federal authorities would not intervene. The Federal Charter is the property of Canton Schwyz.
Presence Switzerland, the federal government's agency charged with promoting the image of Switzerland abroad, wants to display the Latin-language document in Philadelphia at an exhibition in June to mark the launch of its Swiss Roots initiative.
This project aims to bring the million Americans of Swiss origins closer to their ancestors' homeland, the centrepiece of which will be a genealogical website.
Johannes Matyassy, chief executive of Presence Switzerland, said he was confident that the charter would return home safely.
"If we're capable of sending the Swiss president to the US and getting him back home safe and sound, I'm sure we'll manage to get the Federal Charter back safely as well," he told public television.
The first Swiss Federal Charter, also known as Letter of Alliance, was written in 1291.
It documents the union of three cantons of what is now central Switzerland. The alliance was set up for defence purposes.
The letter is on permanent display in a museum in the central town of Schwyz near the mythical birthplace of Switzerland. The authenticity of the charter is disputed.
Other federal charters were written in the subsequent years from 1291 to 1513.
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