A statement that party chief Alexis Tsipras is an atheist has led to a war of words from political opponents and a flurry of comments on social media.

"The government is reaching its end main opposition (SYRIZA) party leader Alexis Tsipras said on Thursday in a discussion in parliament on banking scandals.

Main opposition Radical Left Coalition (SYRIZA) MP Petros Tatsopoulos on Thursday submitted his resignation from the party to SYRIZA leader Alexis Tsipras.