Far-left rebels in Greece's Syriza party have broken away to form a new party with 25 politicians, a parliament deputy speaker announced on Friday.
The new party will be called Popular Unity and headed by former Energy Minister Panagiotis Lafazanis, the leader of the far-left faction within Syriza that has defied outgoing Prime Minister Alexis Tsipras's call to back a third bailout programme.
It comes after Tsipras resigned on Thursday.
With 25 politicians, the party would be the third largest block in Greece's 300-seat parliament ahead of the centrist To Potami and far-right Golden Dawn parties, which each have 17 politicians.
A far-left faction of Greece's ruling Syriza party is to form a new political party.
Some 25 politicians will leave Syriza and become independent, state TV reported.
It comes after Syriza leader Alexis Tsipras resigned as Greek Prime Minister yesterday to force a snap election next month.
Greek MPs have overwhelmingly approved a new batch of reforms demanded by the country's international creditors in return for a third multibillion-euro bailout.
The vote followed a whirlwind debate that ended at 4am local time.
Prime Minister Alexis Tsipras once again suffered a revolt in his own radical left party, but had no trouble passing the draft legislation with the backing of pro-European opposition parties.
The reforms were the final prerequisite before Greece can start negotiations with creditors on a third bailout worth around 85 billion euro (£59.5 billion).
Government spokeswoman Olga Gerovasili conceded there is a clear rift within Syriza, but would not say whether rebels would be expelled.
"From this point on, party procedures will be followed in order to deal with the problem," she said after the vote.
The Greek parliament will vote today on a second set of reforms needed to secure its bailout deal.
If MPs approve the financial and judicial reforms, Greece will be able to forge ahead with negotiations for an €86 billion bailout from its creditors.
Prime Minister Alexis Tsipras rallied his Syriza colleagues earlier this week , saying the Greek people had "pinned their hopes" on staying in the euro.
The vote is expected to pass with the support of opposition parties.
Greek Prime Minister Alexis Tsipras is facing increasing pressure from MPs - including many from his own party - as they debate ahead of a key vote on the bailout deal agreed with the country's creditors.
Amid anger over the deal - which requires a new raft of austerity measures - his own deputy finance minister resigned today, saying she could not vote in favour.
Other ministers within Tsipras' Syriza party have also said they will not vote in favour of the measures, while one rival MP from right-wing Golden Dawn party ripped up a copy of the deal in the chamber before throwing it in the air.
Speaking as he tore up the "despicable document", Ilias Kasidiaris said: "They [international creditors] are not going to get anything from Greece and those despicable memoranda to which the Greek people said no will send you and your policy to the rubbish bin of the Greek history."
Former finance minister Yanis Varoufakis also spoke during the debate, calling the deal a "continuation of debt slavery" before one heckler shouted "traitor" and "the man who brought us here".
Germany is trying to humiliate Greece by bringing new demands for a bailout deal, Dimitrios Papadimoulis, Vice-President of the European Parliament and member of Greece's ruling Syriza party, said.
Highlighting the depth of reluctance to grant another rescue to Greece, Germany's finance ministry put forward a paper today demanding stronger Greek measures or a five-year time-out" from the euro zone that looked like a disguised expulsion.
"What is at play here is an attempt to humiliate Greece and Greeks, or to overthrow the (Prime Minister Alexis) Tsipras government," Papadimoulis told Mega TV.
The Greek Prime Minister has said that a positive outcome in negotiations over the country's debt crisis is the "priority". Alexis Tsipras claimed a strong mandate to complete negotiations with international creditors after winning the backing of parliament over a painful new package of reform measures.
In a statement issued after the vote in parliament, which the government won with the help of pro-European opposition parties, he said he had a "strong mandate to complete the negotiations to reach an economically viable and socially fair agreement".
He made no mention of rebels within his own leftwing Syriza party who withheld support for the measures but said his focus was on completing the negotiations.
"The priority now is to have a positive outcome to the negotiations. Everything else in its own time," he said.