"I am resigning as a Syriza MP, I am not resigning from political action," Alexis Tsipras said in a statement on Monday.
Former Greek Prime Minister Alexis Tsipras has resigned from his parliamentary seat, fuelling speculation that he will form a new political party.
In his announcement on Monday, Tsipras said he was stepping down as a Syriza member of parliament, but "not resigning from political activism".
"I cannot, and I do not want to, formally participate in a parliament that, democratically stripped bare, mainly at the responsibility of the majority, is unable to perform the role that the constitution prescribes and the citizens demand," he said in a statement.
Later on Monday, the leftist told his former colleagues: "We will not be rivals. And perhaps soon we will travel together again to more beautiful seas."
His remarks come amid growing rumours in Greek media that Tsipras will launch a new party with the aim of leading the country's centre-left and left.
Tsipras became leader of Syriza in 2008 at the age of 34. He served as Greek prime minister from 2015 to 2019 during politically tumultuous years as the country struggled to remain in the eurozone and end a series of international bailouts.
In June 2023, he stepped down as leader of Syriza after the party suffered a crushing defeat in the general election to the ruling centre-right New Democracy party. Syriza has since fractured and been usurped as Greece's main opposition party by the socialist PASOK party.
While New Democracy still appears comfortable in polls, despite a recent drop in popularity, Tsipras could challenge Prime Minister Kyriakos Mitsotakis if he were to form a new party.
Polls indicate that Tsipras' potential base could comprise up to 20% of Greek voters, according to local media reports, ahead of the next elections in 2027.
The parliamentary seat vacated by Tsipras is set to be filled by Thodoris Dritsas, a former shipping minister who represented Syriza but is now affiliated with the New Left.
That would give the New Left a total of 12 MPs, leaving Syriza with 25, local media reported.