Some 7,000 police officers are going to be placed on duty for the visit of German Chancellor Angela Merkel to Athens on Tuesday.
A number of protests have been planned to coincide with Merkel?s trip and the government wants to ensure that the event passes off without major incident.
Police officers will be brought in from outside Athens as the government steps up security measures for the chancellor?s first trip to Greece since 2007.
The country?s two largest unions, GSEE and ADEDY, have called for a three-hour work stoppage from noon so members can take part in a rally at Syntagma Square in central Athens at 1 p.m.
Members of the Communist Party-affiliated union, PAME, will hold a separate demonstration at 1 p.m., at Omonia Square.
Merkel is due to meet President Karolos Papoulias at noon and Prime Minister Antonis Samaras at 2 p.m. The two leaders are due to hold a news conference after their talks.
Leftist SYRIZA has encouraged its supporters to take part in the protest and vent their dissatisfaction with the austerity measures being implemented in Greece.
The right-wing Independent Greeks have called for a human chain to be formed around the German embassy in Athens as part of a symbolic protest against Merkel?s decisions regarding Greece.
However, Democratic Left, the coalition government?s junior partner, has voted not to protest. One if its MPs, Yiannis Micheloyiannakis, who has said he will vote against the latest austerity package, proposed at a meeting of the party?s central committee over the weekend that a protest be held at the German Embassy. His motion failed to gather any votes of support.
The coalition is hoping that Merkel?s visit will act as a visible sign of support for Greece going into a crucial few weeks, when the 13.5-billion-euro austerity package is to be finalised and the troika is due to issue its report on Greece ahead of a decision on the disbursement of the next loan instalment for Athens.
However, German Finance Minister Wolfgang Schaeuble insisted on Sunday that Merkel?s visit to Athens did not mean that the disbursement of Greece?s next bailout tranche was a given.
"The chancellor will not discuss with Greece a matter which the troika must report on first,» Schaeuble told broadcaster ZDF in an interview.
"Greece must fulfill its obligations for the next tranche to be paid,» said Schaeuble.