Unions have claimed that hundreds of employees have already left their posts via transfers, pursuant to the public transport reform law.
The metro, the ISAP electric railway, buses, trolleys, the tram line, the Proastiakos suburban rail and OSE trains will not run for 24 hours.
Taxi owners also announced a 48-hour strike for Wednesday and Thursday, protesting against the deregulation of their sector.
Meanwhile, Infrastructures, Transport & Networks Minister Yiannis Ragoussis called on transport sector workers to display a "sense of responsibility" and make their decisions with the general interest in mind.
He also underlined that the public transport sector continues to generate deficits expected to reach 150 million euros in 2011, characterising the situation as "borderline".
Public transport strikes prevent student assemblies, extend sit-ins
Student assemblies to decide whether to continue sit-ins underway at several universities and university departments had to be postponed on Tuesday due to a public transport strike that brought Athens to a virtual standstill for those without cars.
Among the schools where sit-ins are continuing are the Athens Technical University (NTUA) and the Athens Economics University, where student assemblies have been postponed until Thursday.
Sit-ins are currently underway at 154 departments and universities, with a strong risk that the entire examination period and semester will be lost.
At the same time, sit-ins at highschools are multiplying. There are currently 405 schools occupied by school students, of which 174 are in the Attica area. The education ministry is concerned about the prospect of contagion of sit-ins to all schools within a few days.
Metro workers' strike ruled illegal
Tuesday's strike by Athens metro workers was ruled illegal by a decision of an Athens court issued around the middle of the day, after the management STA.SY SA took legal action against the strike that was officially declared late on Monday.
Based on the court's ruling, the management is now calling the workforce to return to their posts and run the Athens metro. The employees, on their part, said that the union has not yet been officially notified of the court's decision and, even in the case that this happens, it will be extremely difficult to find sufficient workers at this time in order for the metro to run safely.
In the meantime, STA.SY has also asked courts to rule against a 24-hour strike declared by workers on the metro, tram and ISAP electric railway on Wednesday.
This case will be heard on Wednesday morning and a ruling is expected to be issued in the afternoon.
Border and special guards hold protest rally outside Parliament
Border guards and special guards held a protest rally in front of the entrance to Parliament on Tuesday afternoon.
Uniformed people from all over the country protested, shouting slogans and holding banners, with their main demands being the lifting of deductions imposed on them and the "freezing" of salary promotions, while calling for "the determining of a minimum survival salary for the policeman" and the suspension of uniformed people's housing loan instalments, to the point that it will be considered safe for them.