Strikes a barometer of Europe's austerity tolerance
Across Europe people are taking to the streets to express their anger and frustration with austerity.
There will be disruption and protests. General strikes have been called in Spain and Portugal, and there will be action in Greece, Italy, Belgium and France.
The day will serve as a barometer of the mood in Europe.
Is it increasingly angry? Or just resigned?
The question that worries many of Europe's leaders is when will patience run out? When will tolerance of high unemployment and declining living standards snap?
The eurozone's strategy still holds. Deficits must be reduced. Structural reforms - such as the opening up of labour markets - are the key to future growth.
Countries must regain their competitiveness with Germany by slashing wages and pensions.
The European Commission believes that austerity may hurt growth in the short term, but in the longer term it will revive confidence in Europe.
It remains a hugely controversial policy. There are those who say it has failed in Greece.
There, the economy has shrunk by 23% in five years. Many economists insist it is madness to continue with austerity when so many southern European countries are already in recession.
Spain has an unemployment rate of 25% and is in recession. In five of its 19 regions, unemployment stands at more than 30%.
Yet the government in Madrid is embarking on another round of spending cuts that will only further weaken demand.
The human cost of those policies has been underlined in the past two weeks by two suicides linked to the repossession of homes.
The protesters will march behind the slogan, "They are taking away our future".
The Greek prime minister, while pushing austerity measures through parliament in recent days, has also said he accepts his country is facing the equivalent of the Great Depression.
Recently, the IMF conceded it had underestimated the impact of austerity on living standards and there are signs of greater flexibility in the eurozone.
Deficit-cutting targets for Spain, Greece and Portugal have been eased.
Brussels is said to have moved towards an "austerity-lite" policy, but the fundamentals stand. Southern Europe has to reduce its deficits and debts.
The key question remains; how will growth be restored?
Without it, Europe faces a future of hardship. German Chancellor Angela Merkel has said the eurozone crisis may last five years.
She has just visited Portugal, where she praised the sacrifices being made and promised that one day the "painful" changes would be positive, but she was booed during her visit.
A youthful generation may not be prepared to accept unemployment at more than 50% for five years or longer.
In the past three months the eurozone crisis - as reflected by the markets - has eased. The economic outlook, however, has worsened.
Wednesday's day of action will be watched closely to gauge Europe's mood.