Greek PM George Papandreou is facing calls from senior members of his own party to resign, amid uncertainty about a eurozone bailout deal. Earlier the BBC reported that the PM was preparing to resign but state TV said he had ruled this out. The opposition New Democracy party has said it would accept taking part in a coalition government if Mr Papandreou agreed to stand down.
Mr Papandreou is due to meet MPs from his Pasok party at 17:00 local time (15:00 GMT), after which he is expected to speak to parliament ahead of a confidence vote on Friday.
Pasok holds a slim majority in parliament, 152 out of 300 seats.
But Mr Papandreou was faced with a parliamentary revolt after several of his MPs withheld their backing. Some called for early elections or a government of national unity instead.
Reports say he is now prepared to drop the referendum proposal.
New Democracy leader Antonis Samaras called for a caretaker government to safeguard the EU deal.
Earlier, the chairman of the group of eurozone countries, Jean-Claude Juncker of Luxembourg, said plans were in place for a Greek exit from the euro.
Greece was due to receive the next tranche of funds from its first bailout later this month. However, the EU has said it will not transfer the 8bn euros until after the referendum.