Yemen's General People's Congress, the party of former president Ali Abdullah Saleh, has rejected the newly formed government, announcing that the party's majority parliamentary bloc will not support a confidence vote backing it.
Earlier on Saturday, President Abdrabuh Mansur Hadi was dismissed from the same party, after being accused of soliciting UN sanctions against his predecessor Saleh.
The GPC said it had appointed two members to the posts of vice president and secretary-general in place of Hadi, who became president after Saleh was forced to resign in February 2012 after a year of bloody protests.
The Shia Houthi rebels, who are in control of the capital Sanaa, also rejected the new government in its current form, calling for a cabinet reshuffle and the removal of a number of newly appointed ministers.
"This cabinet is disappointing and did not adhere to the agreed criteria of the peace and national partnership agreement," a Houthi statement said.
Yemen, which has been in political turmoil due to clashes between rival factions, had announced the formation of a new government on Friday after weeks of unsuccessful attempts.
Key players, including the Houthi rebels, had signed an agreement on November 1, mandating the president and prime minister to form the new technocratic government.
"The situation provides President Hadi with limited options," Al Jazeera's Hashem Ahelbarra, reporting from Sanaa, said.
"He will likely engage with his former party for a compromise if his predecessor does not change his position."
Later on Friday, the UN Security Council imposed sanctions on Saleh and two allied Shia Houthi rebel commanders for threatening the peace and stability of the country and obstructing the political process.
Saleh, Abd al-Khaliq al-Houthi and Abdullah Yahya al-Hakim are now subject to a global travel ban and asset freeze.
Saleh denied seeking to destabilise Yemen and his party had warned that any sanctions on the former president or "even waving such a threat would have negative consequences on the political process".
The UN decision came after thousands of Saleh and Houthi supporters filled the streets of Sanaa to protest against the move to punish the former leader, accused of being the main backer of the Houthi rebels who have seized large parts of the country, including the capital.
Source: Al Jazeera and agencies