Video|Greek MPs face second austerity vote amid mounting protests

Greece needs this vote to implement the measures already agreed upon in order to secure the country further financial support, as represents a a retreat from the "grave scenario of default", the EU has said.

Public reaction to the austerity measures has been very hostile, and the debate has been accompanied by strikes and violent protest. In the meantime, clashes continued on Syntagma Square outside parliament overnight, as police fired tear gas at stone-throwing youths.

MPs are not expected to vote before 1400 local time (1100 GMT), and it is not clear how many votes will need to be held to push the measures through.

Government officials however say they are confident that those who supported them in Wednesday's vote, when the package was approved in principle by 155 votes to 138, would also vote for implementation.

Also, the opposition New Democracy party, which voted against the government on Wednesday, has said that it will support some elements of the bill involving privatisation and spending cuts.

The vote will enable Greece to receive the latest bailout of a €110 billion (£98bn) loan in time instead of defaulting on the bailout already taken.

But analysts say the real challenge will come after the loan is secured, and there is concern about whether the austerity measures can be effectively implemented in the face of so much public hostility.

Wednesday's vote prompted a furious response from protesters in Athens.

Sporadic violent clashes were continuing in the capital in the early hours of Thursday between masked protesters - armed with stones and sticks - and riot police firing tear gas and stun grenades.

Despite the unrest, European Commission President Jose Manuel Barroso and European Council President Herman Van Rompuy welcomed the result as a "vote of national responsibility" paving the way for a second aid package.

The package of tax rises and budget cuts - worth about €28 billion over five years - had been championed by Greek Prime Minister George Papandreou.

Had it been rejected, Greece could have run out of money within weeks. The EU and the International Monetary Fund have demanded that the measures are implemented before they extend further loans to Greece.

Greek unions are angry that the government's austerity programme will impose taxes on those earning the minimum wage, following months of other cuts that have seen unemployment rise to more than 16%.

Once passed, European officials will start to finalise the details of a second bail-out, worth an estimated €120 billion, designed to help Greece pay its debts until the end of 2014.