Portugal's centre-right government faces a no-confidence motion in parliament on Wednesday brought by the opposition Socialists over mounting unhappiness with the recession-plagued country's austerity measures.
The motion is almost certain to be defeated by the ruling coalition, which enjoys a comfortable majority.
But the move exposes growing dissent over the austerity policies imposed on Portugal since it received a 78-billion-euro ($101 billion) international bailout agreed in May 2011.
"The time has come to put an end to the austerity policies that are impoverishing our country and demand heavy sacrifices from the Portuguese people without them seeing any results," the Socialist Party said in the motion.
The Socialists were in power when Lisbon sought the bailout but they now accuse Prime Minister Pedro Passos Coelho's government of an "excess of austerity", which they blame for worsening the recession and unemployment.
According to official forecasts, the Portuguese economy will shrink by 2.3 percent this year and the unemployment rate, now at 16.9 percent, will climb to 18.2 percent.
Last month, Portugal won an extra year from its creditors to bring down its public deficit in line with EU regulations. The government now targets a deficit of 5.5 percent of gross domestic product (GDP) in 2013.