KUWAIT CITY: Kuwait's prime minister formed a cabinet Saturday that retained all ruling family ministers, following elections in which the opposition performed well on pledges to oppose austerity measures.

Prime Minister Sheikh Jaber Mubarak Al-Sabah appointed seven new figures including Essam al-Marzouk as minister of oil, electricity and water. Marzouk, a member of a merchant family, was head of the Kuwait Bourse Company and on the board of national oil conglomerate Kuwait Petroleum Corp. In addition to the prime minister, the cabinet includes five members of the Al-Sabah family which has ruled Kuwait for two and a half centuries, the same number as in the previous cabinet.

But former interior minister Sheikh Mohammad Khaled Al-Sabah was moved to the defence ministry, apparently after opposition lawmakers vowed to grill him over the removal of citizenship from opposition activists. The previous defence minister, Sheikh Khaled Jarrah Al-Sabah - also a member of the ruling family - took the interior portfolio.

Foreign Minister Sheikh Sabah Khaled Al-Sabah, a royal, kept his post.

Anas al-Saleh remained finance minister despite strong criticism for his economic policies which included cutting subsidies and raising the price of petrol.

Several MPs have vowed to question him if he was retained in the cabinet.

The Islamist-dominated opposition has vowed to oppose the government's austerity measures in the face of low oil revenues.

At the cabinet's first meeting, the prime minister called for rapid measures to diversify the economy away from oil, which generates around 90 percent of public revenues.

MPs have said they will not allow the government to impose new charges or cut generous welfare payments to citizens despite falling oil prices.

Several lawmakers criticised the new cabinet.

"We have been disappointed as we expected to see a strong government to meet our aspirations," MP Mubarak al-Hajraf said.

MP Youssef al-Fadhalah tweeted that "The prime minister failed to read the outcome of the election and the verdict of the people in rejecting the previous cabinet and parliament."

The government of the oil-rich Gulf state resigned last month following the November 26 general election in which the opposition and its allies won nearly half the seats in parliament.

The 50-member legislature is scheduled to meet Sunday, when ministers will swear oaths to become members of parliament - although 15 of the 16 are unelected.

The reappointment of Prime Minister Sheikh Jaber, 73, who has held the post since late 2011, came despite calls from a number of opposition MPs for a new premier to reflect the result of last month's polls.

Opposition groups boycotted two general elections in 2012 and 2013 in protest at a change in the voting system brought unilaterally by the government.

Under Kuwait's constitution, the emir has the sole power to appoint the premier, regardless of the outcome of polls.

The new cabinet is not required to be submitted to a vote of confidence in parliament.