ATHENS — Parliament appeared close to approving and carrying out a set of unpopular austerity measures after a day of intense political maneuvering on Tuesday that seemed to bring wavering members of the ruling Socialist Party into line. 
 
 While the lawmakers debated, riot police clashed with protesters outside the Parliament building. Parliament must pass the measures — which include wage cuts, tax increases and privatizations in a recession-starved country — before Greece’s foreign lenders unlock the next installment of aid that the country needs to avoid default. 
 
 Prime Minister George A. Papandreou has a five-vote parliamentary majority as he tries to push through the austerity plan, which strikes at the heart of his Socialist Party base. The center-right New Democracy opposition party has struck a populist tone and opposes the measures, saying they offer too much austerity and not enough stimulus. 
 
 In the tense countdown ahead of the vote to approve the austerity package, which is scheduled for Wednesday, at least one member of Parliament from the Socialist Party who had opposed the bill changed his mind. 
 
 The lawmaker, Thomas Robopoulos, told state television on Tuesday that he would support the measures, “putting the national interest above everything else.” Earlier, Mr. Robopoulos had said he would decide “at the very last moment, after I have listened to all the speakers,” referring to the debate in Parliament. 
 
 “This is a crucial moment; if the memorandum does not pass we shall go bankrupt,” Mr. Robopoulos added. 
 
 He spoke after talks with the new finance minister, Evangelos Venizelos, a longtime Socialist who is regarded as being able to rally the party behind the measures, however unpopular. 
 
 The nation’s unions complicated matters on Tuesday when they began a 48-hour general strike — the first time they had walked out for more than 24 hours since democracy was restored to Greece in 1974 after a seven-year military dictatorship. 
 
 The protests in Syntagma Square in front of Parliament began peacefully but turned violent as groups of youths on the fringes began throwing rocks, firebombs and firecrackers. 
 
 The European Union, the European Central Bank and the International Monetary Fund have said they will release $17 billion that Greece needs to pay its expenses through the summer if Parliament passes the measures. 
 
 “The only way to avoid immediate default is for Parliament to endorse the revised economic program,” said Olli Rehn, the European Union’s top economic and monetary affairs official. “Let me say this clearly: There is no Plan B to avoid default.” 
 
 In Brussels, European Union officials said they were working on contingency plans, including an effort to persuade the Greek opposition leader Antonis Samaras of the New Democracy Party to support the measures. 
 
 After the vote on the austerity measures, Parliament is scheduled on Thursday to consider a bill on how each of the measures will be carried out. Last year, Greece’s foreign lenders imposed austerity measures after they provided a first round of aid. 
 
 Since then, Greece has cut the wages of its 800,000 public workers — a quarter of the work force — by more than 10 percent. 
 
 The demonstration on Tuesday was one of the first in which labor unions joined with the younger demonstrators who have gathered in downtown Athens every night for the past month. Security forces fired tear gas to thin out the crowd, sending the demonstrators fleeing into side streets. 
 
 A police official said that 23 people were detained, with five later arrested, and that 21 officers were injured, none seriously. 
 
 Near Syntagma Square, a 40-year-old woman who gave her name only as Eirini, said she had been a secretary in a construction firm but had been out of work for more than five months. 
 
 “I’m here because we have nothing to lose,” she said, pushing down the surgical mask she used to filter out the tear gas. “We know very well that in six months, when they run out of money in the banks, we will be even more broke and hungry.” 
 
 She added, “I think that in one year, we are going to go to Syntagma, take out all the grass and plant tomatoes.” ||||| Riot police fired tear gas at youths hurling rocks near the Greek finance ministry Tuesday, trying to quell the anger unleashed by a general strike as parliament debated new cost-cutting measures. 
 
 A demonstrator kicks a tear gas canister against police during a demo in Athens on Tuesday June 28, 2011. Greece's beleaguered government is bracing for a 48-hour general strike as lawmakers debate a... (Associated Press) 
 
 Demonstrators run away from tear gas during a demo in Athens on Tuesday June 28, 2011. Greece's beleaguered government is bracing for a 48-hour general strike as lawmakers debate a new round of austerity... (Associated Press) 
 
 Demonstrators pull an umbrella as another burns during a demo in Athens on Tuesday June 28, 2011. Greece's beleaguered government is bracing for a 48-hour general strike as lawmakers debate a new round... (Associated Press) 
 
 Greek soldiers wearing traditional military uniforms march during a ceremonial changing of the guard at the Tomb of the Unknown Soldier at the foot of the Greek parliament building as protesters (in foreground)... (Associated Press) 
 
 A protester sits outside the docked ships during a 48-hour strike in the port of Piraeus, near Athens, Tuesday, June 28, 2011. Workers across Greece walked off the job Tuesday at the start of the 48-hour... (Associated Press) 
 
 Tourists pass outside the ships during a 48-hour strike in the port of Piraeus, near Athens, Tuesday, June 28, 2011. Workers across Greece walked off the job Tuesday at the start of the 48-hour general... (Associated Press) 
 
 Pedestrians cross empty rails at the train station in Athens during a strike Tuesday, June 28, 2011. Public transport workers joined a nationwide 48-hour general strike as lawmakers debate a new round... (Associated Press) 
 
 Tourists from Australia sleep outside the ships during a 48-hour strike in the port of Piraeus, near Athens, Tuesday, June 28, 2011. Workers across Greece walked off the job Tuesday at the start of the... (Associated Press) 
 
 Passengers change their tickets at Olympic Air's cashiers during a four-hour work stoppage by air traffic controllers at the Athens International Airport Tuesday, June 28, 2011. Workers across Greece... (Associated Press) 
 
 Demonstrators run away from tear gas during a demo in Athens on Tuesday June 28, 2011. Greece's beleaguered government is bracing for a 48-hour general strike as lawmakers debate a new round of austerity... (Associated Press) 
 
 Passengers sleep during a four-hour work stoppage by air traffic controllers at the Athens International Airport Tuesday, June 28, 2011. Workers across Greece walked off the job Tuesday at the start of... (Associated Press) 
 
 Demonstrators throw stones against police during a demo in Athens on Tuesday June 28, 2011. Greece's beleaguered government is bracing for a 48-hour general strike as lawmakers debate a new round of austerity... (Associated Press) 
 
 Riot police take position outside the Greek Parliament prior of a demo in Athens on Tuesday June 28, 2011. Greece's beleaguered government is bracing for a 48-hour general strike as lawmakers debate a... (Associated Press) 
 
 The latest austerity measures must pass in two parliamentary votes Wednesday and Thursday if Greece is to receive bailout funds from the EU and the IMF that will keep it from becoming the first eurozone nation to default on its debts. 
 
 The clashes with police came at the start of a two-day general strike called by unions furious that the government's new euro28 billion ($40 billion) austerity program will slap taxes on minimum wage earners and other struggling Greeks. The measures come on top of other spending cuts and tax hikes that have sent the Greek unemployment rate soaring to over 16 percent. 
 
 Hooded youths ripped up paving stones and set trash bins on fire in central Athens as police gave chase and fired tear gas and stun grenades. Earlier, about 20,000 people had marched peacefully in two separate demonstrations, while another 7,000 protested in the northern city of Thessaloniki without incident. 
 
 Everyone from doctors and ambulance drivers to casino workers and even actors at a state-funded theater were joining the strike or holding work stoppages for several hours. 
 
 Hundreds of flights were canceled or rescheduled as air traffic controllers walked off the job for four hours in the morning _ and were holding another walkout in the evening. Strikes by public transport workers snarled traffic across the capital, while other protesters blockaded the port of Piraeus. 
 
 "The situation that the workers are undergoing is tragic and we are near poverty levels," said Spyros Linardopoulos, a protester with the PAME union at the Piraeus blockade. "The government has declared war and to this war we will answer back with war." 
 
 Lawmakers began debating the latest austerity measures Monday and were continuing Tuesday. The package and an additional implementation law must be passed so the European Union and the International Monetary Fund release the next installment of Greece's euro110 billion ($156 billion) bailout loan. 
 
 Without that euro12 billion ($17 billion) installment, Greece faces the prospect of a default next month _ a potentially disastrous event that could drag down European banks, hurt other financially troubled European countries and even shock the whole global financial system. 
 
 But even lawmakers from the governing Socialists have been upset over the latest measures demanded by international creditors, and Prime Minister George Papandreou has struggled to contain an internal party revolt. He reshuffled his cabinet earlier this month to try to ensure his party's support for this vote, but the Socialists still only have a 5-seat majority in the 300-member Parliament. 
 
 Papandreou urged lawmakers Monday to fulfill a "patriotic duty" by voting in favor of the new measures, but two of his own lawmakers have suggested they won't. 
 
 European officials have also been pressuring Greece's the main conservative opposition party to back the austerity bill. 
 
 "Both the future of the country and financial stability in Europe are at stake," European Monetary Affairs Commissioner Olli Rehn said. "I fully respect the prerogatives and the sovereignty of the Greek Parliament in the ongoing debate. And I trust that the Greek political leaders are fully aware of the responsibility that lies on their shoulders to avoid default." 
 
 But conservative party leader Antonis Samaras has refused, arguing that while he backs some austerity measures, the overall thinking behind the package is flawed. 
 
 Greece remains frozen out of bond markets and is surviving on the euro110 billion ($156 billion) in promised bailout loans. But the initial plan had assumed that Greece would be able to return to the markets next year. 
 
 That won't happen, and a result Athens is negotiating for a second bailout, which Papandreou has said will be roughly the same size as the first. 
 
 Papandreou said he hoped the terms would be better than those for the first bailout. 
 
 "I call on Europe, for its part, to give Greece the time and the terms it needs to really pay off its debt, without strangling growth, and without strangling its citizens," he said. 
 
 Papandreou's new finance minister, Evangelos Venizelos, said the government acknowledged the new cuts were "unfair" and that he hoped negotiations over a second bailout would be concluded by the end of the summer. 
 
 "These measures will take us from running budget deficits to achieving primary surpluses," he said. "It's a difficult but necessary step." 
 
 But many Greeks insist they should not be forced to pay for a crisis they believe the politicians are responsible for. 
 
 "We don't owe any money, it's the others who stole it," said 69-year-old demonstrator Antonis Vrahas. "We're resisting for a better society for the sake of our children and grandchildren." 
 
 Even with the new austerity measures, many investors still believe that Greece is heading for some sort of default because its overall debt burden is too great. 
 
 ___ 
 
 Demetris Nellas in Athens contributed.
– Greek workers launched a 48-hour general strike today to protest government austerity measures as 20,000 demonstrators headed to Parliament and another 7,000 marched in the country’s second-biggest city. Some 5,000 police guarded Athens, and while the initial protests were peaceful, things are heating up. Young people threw rocks near Greece’s finance ministry, prompting tear gas from police; in central Athens youths burned garbage bins. Strikers range from actors to casino workers to doctors, the AP reports. With lawmakers considering a $40 billion austerity program, including new taxes on minimum-wage earners, “the government has declared war and to this war we will answer back with war,” said a protester. Meanwhile, the debate continues in Parliament as European officials push for the plan. "To those who speculate about other options,” noted one, “let me say this clearly: There is no Plan B to avoid default," the New York Times reports. But protesters argue the country’s debts aren’t theirs to cover. “We don't owe any money, it's the others who stole it,” said one.