Greece's Prime Minister Alexis Tsipras said on Thursday that he will resign immediately, opening the way for early elections, ekathimerini.com reported.

Tsipras, who made the announcement in a televised address to the nation, is due to hand his resignation to President Prokopis Pavlopoulos later on Thursday.

The snap election is expected to take place on 20 September, according to earlier Greek media reports.

Tsipras, leader of leftist SYRIZA party, took office as prime minister on 26 January.  His coalition government has the support of less 120 members of the 300-seat parliament and has to rely on opoposition MPs to pass legislation.

With a third bailout deal with Greece's creditors now secured, Tsipras said it's his moral duty to go to the polls. 

The terms of the bailout deal that include painful austerity measures such as tax hikes and pension cuts have angered some members of SYRIZA, denting support for the party in parliament.

The new parliamentary elections, the sixth in eight years, “will plunge Greece back into short-term political uncertainty but they could allow Tsipras to capitalise on his enduring popularity in the hope of yielding a more stable government that is not held back by far-left critics of the rescue terms,” the Financial Times commented in its coverage of the news.