Under Swiss constitutional law, at least eight cantons must unite in order to call a cantonal referendum, a legal measure that has been in place since 1874 but never successfully used. The cantons took the extraordinary step to prevent the tax cuts depleting their already strained finances still further amid the global economic downturn.

"Up until the late nineties the cantons were able to pass on their expenses to the communities, however, they can no longer afford to take on any more financial burden," Jeremias Blaser of the University of Fribourg noted in a Swissinfo report. As a result of provisions contained in the 2001 fiscal package, which was approved by the Swiss parliament in June, the cantons stood to lose some SFr500 million in tax revenues from tax breaks predominantly benefiting families and homeowners.

Earlier this week, Vaud became the eighth canton to join the campaign, bringing the total number of parliamentarians who voted for the move to 89 (out of 154). Although the motion must be put to a second vote, local observers feel that the final decision is a mere formality. The other cantons to vote in support of the referendum were Basel City, Bern, St Gallen, Graubünden, Solothurn, Valais and Obwalden.