Libya's Prime Minister-elect is to stand down after failing for a second time to win parliamentary approval for a new cabinet.
Mustafa Abu Shagur had called for the formation of an "emergency government", consisting of just 10 ministries.
The General National Congress (GNC) voted 125 to 44 against the proposal. Seventeen members abstained, according to a Libyan national television report.
The GNC now has three to four weeks to elect a new premier.
The national assembly was elected in July in Libya's first free elections in decades, following the overthrow of Col Muammar Gaddafi.
Mr Shagur's second and final offer consisted of just 10 ministries, as opposed to the 29 he offered last week.
Before the vote he told the GNC it was a proposal to lead Libya with no regionalism, and urged members to "assume its responsibilities at this historic time".
His initial cabinet line-up was rejected late on Thursday on the basis that it was not representative of important regions and lacked qualified members.
During the debate, protesters - mostly from the towns of Zawiya and Zuwara - stormed the Congress building in the capital Tripoli, calling for his resignation.
Mr Shagur had initially aimed for a unity government and what he described as "people with merit" to work with him.
However, he said that when he consulted with political parties, some had pursued their own agendas. Without naming them, he said one party had demanded 11 seats, and another had asked for nine.
Mr Shagur said he would not give in to pressure and political games.
"I will not abandon my principles and my convictions. I did not return to Libya [from years in exile] to become head of government, I came back to serve the country and its children," he said.
Mr Shagur studied at the University of Tripoli before moving to the US, where he earned a PhD and worked as an academic and optical engineer.
He returned in 2011 to become an adviser to the National Transitional Council, which was formed during the revolt that ousted Gaddafi.
In September, he was elected by the national assembly to be the country's next prime minister, in a run-off vote in which he narrowly beat Mahmoud Jibril - who served as interim prime minister following the overthrow of the regime.