Greek Prime Minister George Papandreou is holding an emergency cabinet meeting on Thursday, as lawmakers in his ruling socialist party threaten to abandon his government over his controversial plan to put the country’s bailout package to a nation-wide vote.

Socialist lawmaker Eva Kaili of the country’s ruling PASOK party said Thursday that she would not support the government in Friday’s parliamentary vote of confidence, leaving Mr. Papandreou with only a one-seat majority in the 300-member parliament.

Kaili, and a growing wave of other lawmakers and government ministers, want Prime Minister Papandreou to abandon his plans to hold a referendum on an economic bailout deal agreed to by European leaders last week.

Mr. Papandreou called for the referendum and the vote of confidence in order to help quell public backlash against deeply unpopular austerity measures that are part of the bailout package. But analysts now question whether Mr. Papandreou can even survive until Friday’s vote of confidence in parliament.

Another socialist lawmaker, Dimitris Lintzeris, said Thursday that Mr. Papandreou is “history,” and called for a national unity government to be formed.

Earlier Thursday, Greek Finance Minister Evangelos Venizelos broke ranks with Mr. Papandreou on the referendum proposal, saying Greece’s “historic” status in the eurozone should not be determined by a popular vote.

Other Greek Cabinet ministers have previously given their support for the referendum plan.

Mr. Papandreou, who has faced enormous international opposition to the plan, said on Wednesday that Greece’s future in the eurozone is at stake in the vote, but said he is confident that the citizens of Greece will choose to remain in the eurozone.