Greek Democratic Left party leader Fotis Kouvelis on Wednesday urged all political parties in Greece to form a united front for a gradual disengagement from international bailout deals through consultations with creditors to keep the country in the eurozone.

"Our goal is to safeguard Greece's membership in the eurozone and gradually disengage from the memorandum," Kouvelis said when addressing his party's main rally in central Athens in the evening ahead of Sunday's general polls.

The moderate Left leader, who, according to local political analysts, is considered as a possible partner either in a right-wing or a left-wing coalition government after the elections, renewed a plea for the formation of a stable government on June 18 that will ensure Greece's stay in the eurozone.

With conservative pro-reform and pro-bailout New Democracy party and anti-bailout Radical Left Coalition (SYRIZA) running head-to-head, according to opinion polls, the Democratic Left targets the third place up from seventh in the May 6 inconclusive first round of parliamentary elections.

As SYRIZA's call for an abolishment of the memorandum combined with fears of prolonged political stalemate if no party wins again absolute parliamentary majority again and have fuelled anxiety for a Greek default, Kouvelis suggested national consensus.

During Wednesday's rally, he proposed that all party leaders should stand by the side of the new prime minister, no matter who will hold the post, at the forthcoming European Union (EU) summit on June 28.

This way Greece could launch a round of negotiations with counterparts to improve the conditions of the two bailout deals Greece agreed with the EU and the International Monetary Fund since 2010 to avoid a chaotic bankruptcy, he said.