Greek rebel leader Panagiotis Lafazanis is an outspoken former Communist whose staunch opposition to the latest bailout deal split the ruling Syriza party and ultimately forced new elections.
A former student activist, the 63-year-old politician headed the far-left faction of eurosceptic rebels within the radical Syriza party of Prime Minister Alexis Tsipras.
The party, which counted 149 MPs, won elections in January by vowing to end austerity and wipe out the bulk of Greece's massive public debt mountain.
But as Athens came under increasing pressure to appease the country's creditors, the outspoken Lafazanis led an internal revolt, accusing Tsipras the premier of betraying the anti-austerity values that brought him to power.
An implacable foe of the bailout agreement, Lafazanis served as Athens' powerful energy minister until he was removed from his post last month during a cabinet reshuffle over his vocal opposition to the deal.
On Friday, Lafazanis broke free, announcing his own anti-bailout faction called Popular Unity. Formed of eurosceptic rebels, the grouping counts 25 members many of whom are in favour of a return of the Greek drachma.
The new faction is hoping to tap support from the 61 percent of Greeks who voted 'no' to austerity in a July referendum.
"A new power is coming to the fore. We aim for government... and we will not fall victim to blackmail (as Tsipras did)," Lafazanis said.
"We want to become a great movement that will sweep the bailouts aside," he said, listing his party's aims as cancelling the bailouts, erasing Greek debt and even ditching the euro "if necessary" to help the country recover.
Paradoxically, Lafazanis' views on the euro are in line with those of Germany's powerful Finance Minister Wolfgang Schaeuble, who has told Athens the best way to get its economy on track was to stage a temporary exit from the single currency.
- The spirit of 'no' -
With a shock of dark hair and a patchy salt-and-pepper beard, Lafazanis was born in Elefsina, near the port of Piraeus and trained as a mathematician.
In his youth, he took an active role in the movement which resisted the country's military junta that ruled from 1967-1974.
He later joined the Communist Party where he served as a senior member, but left when the party split in 1991.
He then joined Synaspismos, a moderate leftwing group which successfully fielded him as a candidate for Piraeus in 2000.
He was reelected in 2004 and again 2009, but now as candidate for Syriza.
Since leaving the cabinet in July, Lafazanis has been increasingly seen in public in Athens and other places across the country, prompting suspicion he was poised to launch a political campaign.
Last week, he called for the creation of a national anti-austerity movement that would group those disappointed in the steps taken by Tsipras to cut a deal with Greece's creditors.
"We will try to express the spirit of those who voted 'no' to bailouts," he said on Friday.
"It will be our banner. It was not defeated. The Greek people will say a great no again, you can be sure of that."
He is married and has three daughters.