Portugal faces its second general strike in four months on Thursday as workers protest austerity measures and economic reforms agreed by the government in return for an international bailout.
The 24-hour strike is expected to hit public transportation especially hard, with the Lisbon metro train system set to be closed all day, as well as the ferry service linking the two sides of the Tagus river in the Portuguese capital.
Buses and suburban trains will run minimum services but the streets of Lisbon are still expected to be clogged with extra traffic.
Demonstrations are expected in the capital and other main cities.
"We are convinced that we are going to have a high participation rate," said Armenio Carlos, secretary general of Portugal's biggest union -- the General Confederation of Portuguese Workers (CGTP) -- which called the strike.
"It is absolutely necessary to oppose the degradation in the standard of living of the Portuguese people," he said.
The union called the strike in February to oppose changes to labour laws that make it easier to fire workers, reduce holidays and cut layoff compensation, moves the government contends will revive the economy.
It is also angry over government austerity measures such as the elimination of public employees' Christmas and vacation bonuses -- each roughly equivalent to a month's pay -- among measures to rein in the public deficit.
Portugal is locked into a three-year programme of debt-reduction measures and economic reforms in return for a 78 billion euro ($103 billion) financial rescue package from the European Union and the International Monetary Fund.
The centre-right coalition government, which has a majority in parliament, and the main opposition Socialist Party gave their blessing to the bailout conditions in May 2011.
Portugal was the third EU country after Greece and Ireland to receive such a bailout.
Failure to abide by the bailout terms could hold up tranche payments.
The strike comes amid rising concern among analysts and investors that Portugal, like its fellow eurozone member Greece, will need a second bailout -- an eventuality that the government has strongly denied.
Portugal is racing to implement the bailout terms while grappling with the worst recession since its return to democracy in 1974 after decades of dictatorship.
The Portuguese economy is expected to contract by 3.3 percent this year, after falling 1.6 percent in 2011, and push unemployment up to a record 14.6 percent.
More than three million people participated in the last general strike in November 2011, according to the CGTP, which is close to the Communist Party.
But this time around, Portugal's second-biggest union, the historically more moderate General Worker's Union is not supporting the strike because it reached agreement with the government over the labour law reforms.
Past general strikes have affected government departments and public services, including schools and public transport, while banks, shops and almost all private companies have stayed open.
The CGTP says it has 619,000 members. About 300,000 people answered the union's call for a February demonstration in Lisbon, according to the union's estimates.