Liberal Leader Michael Ignatieff is threatening to introduce a motion of non-confidence in the Conservative government as early as next week. Lashing out at the minority Conservatives over employment insurance, isotopes and the deficit, Ignatieff said his party "will make a serene and clear decision" by midweek about whether it wants to topple the Tories. The government's second "report card" on the federal budget's economic stimulus package is due sometime in June. That could be the catalyst for a non-confidence vote.