The Senate has overwhelmingly approved a deficit guarantee of SFr338 for Switzerland's national exhibition in 2002 (expo.02).
The voting was 35 in favour and two against, although the decision was taken apparently without much enthusiasm.
"We do not have any choice and must accept this guarantee grudgingly," said Peter Bieri from canton Zug. He underlined that abandoning the project would cost SFr344 million.
A parliamentarian from Glarus, This Jenny, demanded that lessons be learnt from the exhibition's "financial collapse".
The exhibition was put back by a year after financial support, particularly from the private sector, was slow to materialise. The exhibition has also gone through a number of management changes.
With the deficit guarantee, the Confederation is ready to put a total of SFr718 million at the disposal of the exhibition.
Debate on the guarantee is due to take place in the House of Representatives on June 16.
swissinfo with agencies