ATHENS - Thousands of workers across southern Europe will protest against spending cuts as part of annual May Day rallies on Tuesday, days before elections in Greece and France where voters are expected to punish leaders for austerity.

Unions in Greece, Spain, Portugal and France will use traditional marches to express their anger over an austerity drive across the euro zone, aimed at shoring up public finances but criticised for forcing countries deeper into recession.

Greece's two major private and public sector unions GSEE and ADEDY marched in the capital Athens to mark the national holiday, while the Communist-affiliated PAME group was also holding a separate demonstration.

Greece will vote on Sunday in a parliamentary election that risks derailing an international bailout keeping the country afloat by punishing the parties that backed austerity.

"Our message will be stronger on Sunday," said Maria Drakaki, 45, a public sector worked for 22 years whose salary was cut to 780 euros ($1,000) a month. Many public sector wages have been cut by an average of 25 percent.

"There's no way I'm voting for one of the two main parties on Sunday."

In France, President Nicolas Sarkozy will compete with trade unions to draw the biggest May Day crowd, hoping to steal the limelight from their annual street march before the second round of a presidential election on Sunday.

Socialist Francois Hollande, who is not taking part in the May 1 activities, looks set to beat Sarkozy, who has been in power throughout the euro zone debt crisis.

In Greece, police prepared for violence that has come to mark many rallies, though Athens has not seen major clashes since an unpopular austerity bill was approved in February.

In the capital Athens, buses and trains came to a standstill as transport workers staged a 24-hour strike, while Greek seamen held a four-hour stoppage.

Policy change

The rallies and strike come against a backdrop of growing frustration towards austerity that more fiscally conservative northern euro zone members say is necessary to bring deficits down to meet EU limits and end the debt crisis.

In Portugal, the country's two main labour unions expect tens of thousands of workers to join rallies in the capital Lisbon and other main cities.

The 700,000-strong CGTP union, which refused to sign a pact on labour market reforms required by a 78-billion euro EU/IMF bailout earlier this year, holds its demonstrations under the slogan "Against exploitation and impoverishment, for a policy change!".

The UGT union, which had signed the reform pact with the government, takes its supporters to the streets to demand "Growth and Jobs, Social Justice".

Rallies in Lisbon begin at 1330 GMT. Portugal is implementing tough austerity measures, which have deepened its recession and pushed unemployment to all-time high levels of around 15 percent.

Spain's unions have also called on their members to rally against labour market reforms.

In Greece, repeated rounds of cuts have slashed wages and pensions and deepened a recession that is now in its fifth year.

Private sector wages shrunk by a quarter last year alone, while unemployment has soared to a record 21 percent. One Greek youth in two is out of work.

"These politicians cannot help us. They have nothing new to tell us. They approved the austerity package and the bailout. We are turning our backs on them," said Dina Bitsi, 58, a pensioner with two unemployed sons.  

The country's two biggest parties, the Socialist PASOK and the conservative New Democracy, are expected to barely eke out enough support to renew their pro-bailout coalition, which analysts see as the only viable option for Greece to carry out reforms needed for continued aid and to stay in the euro zone.

Much of the support that the two parties, who have ruled Greece for decades, once enjoyed has now shifted to an array of smaller anti-bailout parties riding high on voter discontent over the austerity measures.

An inconclusive election result could thwart the austerity and reform policies Athens has agreed in exchange for the 130-billion euro bailout that saved the country from bankruptcy.  

Greece's lenders have said that if the country fails to stick to the reforms pledged in return for aid, the country might be forced to abandon the euro.

Most Greeks want to keep the single currency, despite opposing the austerity measures they have been forced to endure since the country's first EU/IMF bailout in 2010.    ($1 = 0.7555 euros)