Embattled Prime Minister George Papandreou made a final appeal for support from wavering deputies on Tuesday ahead of a vote on unpopular new austerity measures that will be held against a backdrop of one of the biggest strikes in Greece for years.

Unions representing around half of Greece's 4 million-strong workforce have called a 48 hour general strike for Wednesday and Thursday to protest against a sweeping package of austerity measures due to be passed in parliament this week.

"I'm asking for your support. I'm asking for all parties' support but we will be the ones who will once again bear the burden of this decision," Papandreou told lawmakers from his ruling PASOK party.

He rejected any suggestion that Greece would be forced out of the euro as a result of the crisis that has left Athens dependent on foreign support to stave off bankruptcy and appealed to European partners for support.

Juggling demands from international lenders for even tougher action and public discontent at home, he has appealed for unity after one socialist deputy resigned in protest of the austerity package and others threatened to vote against parts of it.

"The parliament vote must give us the power to negotiate at the summit," Papandreou said. "This negotiation must end uncertainty and insecurity."

"It's time for Europe to take serious and effective decisions to end the crisis in the euro zone."

A wave of smaller strikes over recent days by groups ranging from rubbish collectors to tax officials, journalists and seamen has given a foretaste of this week's protest which will culminate in mass demonstrations in front of parliament, the scene of violent clashes in June.

The protest, dubbed 'the mother of all strikes' by the daily Ta Nea newspaper, is expected to be the biggest since the financial crisis began two years ago, shutting state offices, shops and even providers of everyday staples like bakers.

Papandreou's struggling Socialist government, trailing badly in opinion polls, has 154 deputies in the 300-seat parliament and is expected to pass the bill, which includes tax hikes, wage cuts, public sector layoffs and changes to collective bargaining rules, in two votes on Wednesday and Thursday.

EU SUMMIT AHEAD

As European Union leaders race to put the foundations of a new rescue plan in place in time for a summit on Sunday, there was growing talk of more direct intervention that would restrict Greek sovereignty in return for more aid.

Trapped in deep recession for the past three years, Greece is choking on a public debt that amounts to around 162 per cent of gross domestic product and there are growing doubts that it will be able to emerge from the crisis without defaulting.

An EU and IMF inspection team left Athens last week, recommending approval of a vital 8 billion euro loan tranche but said Greece was falling behind on its budget targets and should move more quickly to cut spending and pass reforms.

Some euro zone countries have been pressing for a European Commission taskforce to be given direct powers to intervene in areas such as overseeing the sale of state assets.

The Greek government declined to comment on Tuesday but any outside taskforce would need to be ready to counter resistance from a society deeply disillusioned with its own political leaders but also increasingly hostile to outside intervention.

"They've made people want to throw stones at them with these measures. If they were willing to give up their salaries and bonuses, we would probably feel differently about them," said teacher Stamatina Lazopoulou, 36, a mother of two, who will take part in the strike

The latest austerity bill follows a series of painful measures that have so far failed to halt a steady rise in Greece's mountainous public debt and have been attacked by the opposition for stifling any prospect of growth in the stricken economy.

Papandreou met conservative opposition New Democracy leader Antonis Samaras in a bid to present a united front in Brussels. A government official said the premier asked for support on the austerity bill.

The conservatives have ruled out cooperation with the government, saying austerity policies were stifling the economy and the bailout plan must be renegotiated.

Underlining the problems facing an economy that is already forecast to contract 5.5 per cent in 2011, data on Tuesday showed headline unemployment rising to 16.5 per cent in July, a month when summer tourism normally boosts job numbers. Youth unemployment was running as high as 42 per cent.