Greece's ability to pass austerity measures needed to win a new bail-out has been cast into doubt after the prime minister failed to get the full backing of coalition parties. Lucas Papademos held talks overnight with the three party leaders but the issue of pension cuts was not resolved. The government was under pressure to secure a deal ahead of Thursday's meeting of Eurozone finance ministers. Trade unions have announced a 48-hour strike in protest at the measures. Greece needs to have the austerity measures in place to get the 130bn euro ($170bn; £110bn) bailout and avert a default. Overnight talks The prime minister held talks for eight hours on Wednesday night with the leaders of the three parties in Greece's coalition - Pasok, New Democracy and the far-right Laos party. After those talks ended with no agreement on the pension issue, Mr Papademos held a meeting with officials from the "troika" of institutions involved in the bailout - the European Union, the European Central Bank and the International Monetary Fund - which broke up after several hours. The BBC's Mark Lowen, in Athens, says 300m euro (£251m; $398m) savings the government had planned to get from the pension cuts will now have to be found elsewhere. The Greek politicians will not be meeting again on Thursday, he says. The finance minister Evangelos Venizelos will now take only a partial deal to the Eurozone meeting. "I am leaving for Brussels in a short while with the hope that the Eurogroup meeting will be held, and a positive decision on the new programme will be taken," he said. "The financial survival of the country in the coming years depends on the new programme... It is a time of responsibility for everyone." The austerity measures required for the bailout are unpopular with the Greek people, which is making politicians reluctant to support them. The leader of the far-right Laos party, George Karatzaferis, said that he did expect a deal on the pension issue to be reached soon, according to Reuters. He said he expected the deal to be put to parliament "perhaps by Sunday," the agency reports. 'Social uprising' The unions representing around half of Greece's workforce said they were calling a strike for Friday and Saturday, the second this week, because the "painful measures" would "create misery", Reuters reports. "We are moving to a social uprising," a union leader told the agency. The 130bn euro ($170bn; £110bn) bailout deal up for agreement at the moment is Greece's second international bailout and it is the additional austerity measures required for this that are in dispute. The prime minister and finance minister have also been engaged in a separate strand of negotiations with private creditors over a write-off of up to 70% of the value of the money owed by the Greek government.