Tsipras,the leader of a group of Greek far-left parties, which finished second in last week's parliamentary elections, is refusing to take part in more talks to form a coalition government.
Alexis Tsipras said Sunday he will not become what he calls an accomplice in a crime against Greek society. He said those who govern Greece and support the deep spending cuts demanded by the European Union did not get the message of the voters.
Greek President Karolos Papoulias is struggling to broker talks between the three top party leaders to form a new coalition government and avoid another round of parliamentary elections.
None of the top three parties in last week's vote -- conservative New Democracy, radical left Syriza, and the socialist PASOK -- won enough parliamentary seats to form a government.
The talks are scheduled to resume Monday.