Tunisian Prime Minister Hamadi Jebali resigned on Tuesday after his attempt to end a political stand-off by forming a government of technocrats failed.
"I vowed that if my initiative did not succeed, I would resign and ... I have already done so," Jebali told a news conference after meeting with President Moncef Marzouki.
Jebali had proposed the cabinet of apolitical technocrats to quell turmoil caused by the assassination of secular opposition politician Chokri Belaid on February 6.
Belaid's death touched off mass protests targeting in part the ruling moderate Islamist party Ennahda to which Jebali belongs.
No one claimed responsibility for the killing, but it deepened the misgivings of secularists who believe Jebali's government has failed to deal firmly enough with religious extremists threatening the country's stability.
The crisis has disrupted efforts to revitalize an economy hit hard by the disorder that followed the overthrow of veteran strongman Zine al-Abidine Ben Ali in 2011.
Jebali proposed forming a cabinet of apolitical technocrats to restore calm and take Tunisia to elections, but did not consult his own party or its secular coalition partners.
He threatened to quit if the proposal failed. But his party scuppered the plan by rejecting the idea of a technocratic government.
Announcing his resignation on Tuesday, Jebali said he would not lead another government without assurances on the timing of fresh elections and a new constitution.