The Greek parliament on Thursday cleared a bill for the implementation of a new austerity plan approved by lawmakers on Wednesday amidst extensive violent clashes between protesters and police in central Athens.

The bill was ratified along party lines by a vote of 155 in favor, 136 against and five abstentions in the 300-strong assembly with 296 deputies present.

In a new sign of "dissent" within the ruling socialist party which holds 154 seats in the assembly, PASOK deputy Chryssa Arapoglou voted against some articles during Thursday's vote, but approved the overall bill at the end, while an opposition party lawmaker also backed the bill.

The outcome paves the way for the release of further aid to the debt-ridden euro zone member country by the European Union and International Monetary Fund lenders.

The 12-billion-euro (17.38-billion-U.S.-dollar) tranche of the four-year 110-billion-euro (159.31-billion-U.S-dollar) bailout pact Athens secured last year to avoid default and a supplementary package under discussion over the past few weeks, are considered as essential to the rescue of the country from economic collapse this July.

A Greek default would rock the entire European common currency zone. After the positive outcome in Athens, this Sunday in an extraordinary Eurogroup meeting European counterparts are expected to give the "green light" for the release of the fifth tranche of aid and outline the preconditions for the second rescue package.

The painful 28-billion-euro (40.55-billion-U.S.-dollar) mid- term 2012-2015 fiscal strategy plan of spending cuts, tax hikes and a parallel multi-billion privatization program was cleared by 155 positive votes to 138 negative votes on Wednesday.

Despite the positive result, in a blow to the socialist government, one ruling socialist PASOK party deputy voted against the bill and was dismissed from the parliamentary group, leaving Greek Prime Minister George Papandreou a slim four-seat majority in the legislature. The package was backed by an opposition deputy who turned independent.

During Thursday's similar roll-call vote, conservative main opposition New Democracy party deputies backed 21 in 49 articles of the bill regarding privatization of loss-making public companies during the vote procedure, but eventually rejected the package in full, insisting on the prompt renegotiation of the terms of foreign aid to Greece.

As opposition parties and labor unions warn the government that they will continue to resist to the end the implementation of the policies they regard as "recipe to disaster for Greek society," in an effort to appease critics, Greek Deputy Prime Minister and Finance Minister Evangelos Venizelos made some last minute changes to the bill he promoted as "generous measures of social sensitivity."

The government slightly raised the tax-exempt income threshold for families with more than one child and persons with special needs.

For thousands protesters who have taken to the streets for months, denouncing the harsh policies, the changes are not adequate.

"This is like a drop of water in the ocean. They cannot expect us to accept our suffocation with a smile on the face, by giving us one more second of living," commented on Thursday pensioner Spyros Tragakis.

"I worked hard for decades to earn a better future for my children and grandchildren. I will not stop protesting. The crisis was not my fault. They should find other solutions," added Tragakis.

Labor unions scheduled a new rally in front of the parliament building later on Thursday, as the government voices determination to push through the "difficult but necessary" austerity and reform plan to lead Greece out of the crisis.

"Certainly we need measures of social coherence, but when you borrow funds you are obliged to move within a narrow context," Venizelos addressed the assembly on Thursday, repeating a plea for national unity over the austerity measures.

The situation remains difficult for Greece, since there are still no concrete decisions on the further involvement of foreigners into efforts to overcome the Greek debt crisis, he noted.

Despite the positive result at the legislature, amidst the mounting public discontent to measures, Greek media commentators and political analysts talked on Thursday about a short sign of relief which will be soon over, forecasting that new obstacles will be raised in the coming weeks and months.