The two main parties in Greece's ruling coalition would together get just a one-seat majority in parliament if elections were held now, a poll showed on Thursday, less than three weeks before the May 6 vote.

The conservative New Democracy and the Socialist PASOK party, which both back the government of technocrat Lucas Papademos, have seen their ratings drop over recent months because of the unpopular austerity measures imposed in return for a new EU/IMF bailout.

They would jointly win 37 percent of the vote or 151 of the 300 parliamentary seats - a result which would just allow them to renew their coalition, according to a survey by pollster Pulse for Pontiki newspaper.

New Democracy would win 110 seats and PASOK 41, according to the survey, which was conducted on April 11-17. Another opinion poll published on Wednesday showed New Democracy and PASOK winning 158 seats combined.

Eight other parties would pass the 3 percent threshold to enter parliament, the Pulse survey showed, as austerity-hit Greeks turn to fringe parties opposing the bailout.

Seven of the smaller parties that the poll sees entering parliament oppose the austerity plan. They include the extreme right Golden Dawn party, which, the poll showed, would win 15 seats with 5.5 percent of the vote.

The Democratic Alliance, a small centre-right party backing the bailout, would win eight seats with 3 percent of the vote, the poll showed.

Political fragmentation may threaten efforts by the Socialists and the conservatives to form a coalition after the election and implement the prescribed austerity and reform.

Although they oppose the austerity policies set out in the bailout, most Greeks want their country to stay in the eurozone.

After almost two years of belt tightening, Greece is going through its worst recession since World War Two, with record unemployment and painful cuts in pensions and salaries.

[Reuters]