Libya's Tobruk-based parliament has rejected the new cabinet of Abdullah al-Thinni, according to Faraj Hashim, parliamentary spokesman.
Thinni had presented a cabinet with 16 ministers on Wednesday, but members of parliament rejected those names on Thursday.
Thinni, a former career soldier, has been the oil-producing state's acting prime minister since March.
He stood down after June elections and the new parliament reappointed him at the start of this month.
|UN concerned as Libya plunges into chaos
His administration has failed to impose order on a fragmenting country, and many observers fear Libya is heading for civil war.
Libya has two competing governments. The country's former government in the capital Tripoli is refusing to accept the new one in the remote eastern city of Tobruk.
Rebels who backed the rebellion to overthrow Muammar Gaddafi in 2011 have kept their weapons, staking claims to territory, oil and other resources.
An armed group from the western city of Misrata seized the capital Tripoli in August and forced the elected parliament to move to the east of the country.
The Misrata group has set up its own parliament and government, which are not internationally recognised.
As violence continues to flare up in Libya, diplomats gathered in the Spanish capital Madrid to try and find a solution to the crisis.
Representatives from Libya's armed groups, however, failed to attend the conference, which opened on Wednesday and was attended by representative from 16 nations, the UN and the Arab League.
Source: Al Jazeera and agencies