Athens: Greek legislators approved on Saturday an omnibus bill containing a set of prior actions the country pledged to its international creditors in order to unlock the next bailout loan installment in the coming weeks.

The new Left-led government passed the first crucial test since taking office after the September 20 snap general elections, as expected.

All but one of the 155 members of the parliament of the Radical Left SYRIZA party of Prime Minister Alexis Tsipras and the Right-wing Independent Greeks (ANEL) party coalition voted in favour of the bill, while 140 deputies voted against and six were absent, Xinhua reported.

The bill included a new round of tax hikes for all taxpayers that have already caused strong reactions, as well as the introduction of tougher penalties for tax evaders. The bill also contained the framework of a new pension system reform that foresees the gradual phasing out of early retirement and further pension cuts.

Athens has promised to present a new comprehensive plan to overhaul the ailing pension system by the end of 2015.

The new bill paves the ground, foreseeing that retirement age is gradually raised to 67 years for all over the next seven years and those who take an early retirement face a further 10 percent cut on their pensions.

The ratification of the new austerity and reform measures was set as a precondition for the continuation of the review of the Greek programme by lenders that will unlock the first two-billion-euro (about $2.3 billion) aid tranche from Greece's third bailout that was sealed this summer.

Greece has agreed to a three-year aid package totalling 86 billion euros.

In order to secure the new 86 billion euro loans over the next three years to eliminate the risks of default and Grexit, and lead Greece back on the path of development, Tsipras made a U-turn from his party's previous anti-bailout rhetoric in recent months, pledging the quick implementation of the "painful, but necessary" changes.

A party revolt against the third bailout in August triggered the elections just eight months after SYRIZA was first elected in office.

Acknowledging that more pain awaits Greek society after six years of steep recession before the situation improves, the government has pledged to attempt to balance the new losses accumulating from the bailout measures with a parallel programme that will contain policies to support the most vulnerable social groups.

"There are no new measures, but difficult policies which we were all aware of when we voted for the bailout agreement in August. There are tough measures that we are obliged to implement, " Tsipras said, addressing the parliament shortly before the roll call vote.

The Greek prime minister criticised the pro-reform opposition parties for voting against the multi-bill on Saturday, and stressed that the bill opens the path for the conclusion of the bailout review so that the vital new recapitalisation of Greek banks can continue and talks with lenders on debt relief can start.

The opposition parties and labour unions who opposed several provisions of the omnibus bill argued that the prolonged austerity and the kind of reforms will not lead to the revival of the ailing economy rather than the destruction of Greek society.

"We will not compromise, we will not give up. No to the bailout policies," read banners waved by protesters during a protest rally organised by the umbrella union of civil servants ADEDY and Leftist parties outside parliament in central Athens, the Greek capital on Friday evening, while MPs were still debating the bill.