Sinn Féin today announced that it has tabled a motion of no confidence in Minister for Finance Brian Lenihan.
Party president Gerry Adams said the scandalous scale of the bank bailout, which was announced as being €50 billion this week, prompted the decision.
He called on Fine Gael and Labour to support the motion if they were serious about bringing down the Government.
Speaking at a meeting of the party's Ard Comhairle in Dublin, Mr Adams said the Government had "no mandate for what it is doing".
He said the scale of the budget cuts being proposed would deepen the recession.
"Unlike the government parties as well as Fine Gael and Labour, Sinn Féin doesn't accept that cutting €3billion from public expenditure in December's budget is a good idea," he said.
Mr Adams said Sinn Fein would publish a budget alternative, arguing for a stimulus package to create jobs and help ordinary people next month.