Scottish First Minister Alex Salmond has threatened to resign if MSPs do not back his government's first budget.
Mr Salmond's spokesman said he would take the issue "to the people" if the budget fell at Wednesday's crunch vote.
But the Liberal Democrats dismissed the threat as a tactic to divert attention away from "shortcomings" in ministers' spending plans.
Despite Mr Salmond's comments, the minority government is still confident of gaining parliament's backing.
The government warned there would be serious consequences - especially for council funding - if the budget fell at the 1700 GMT vote.
The government claimed the 32 local authorities would lose £144m a month - the equivalent, it argued, of a 22% rise in council tax.
Ministers have already made several last-minute concessions to the SNP's budget following opposition demands.
A total of 1,000 new police officers will be recruited by March 2011 and extra cash will be made available to fight climate change.
And, on the eve of the budget vote, the Conservatives gained a pledge that a new national drugs strategy would be published in the summer, with an emphasis on abstinence programmes and residential rehabilitation.
A Lib Dem spokesman said of Mr Salmond's position: "This is nothing more than an attempt to deflect attention away from the shortcomings of the budget, not least the £1.6bn of efficiency savings which the budget is underpinned by, but which [Finance Secretary] John Swinney has failed to identify."