LAHORE, PAKISTAN -- The eldest daughter and close aide of Pakistan’s former Prime Minister Nawaz Sharif on Monday became the country’s first-ever female chief minister in eastern Punjab province. Her rivals accused authorities of nepotism and boycotted the session of the provincial assembly.

Mariam Nawaz, 50, became chief minister in a 220-0 vote in her favor, beating out her rival Rana Aftab, nominated by the Sunni Ittehad Council and an ally of imprisoned former Prime Minister Imran Khan. Opposition lawmakers supporting Khan, who was ousted in a no-confidence vote in parliament in 2022, boycotted the 371-member Punjab Assembly session Monday.

Nawaz was later sworn in at the provincial governor's sprawling office in the eastern city of Lahore, her father seen next to her along with other family members during the televised ceremony.

Aftab said Nawaz's election was premature as some seats in the assembly reserved for women and minorities have yet be announced. He said her appointment was “yet another case of nepotism as her family is known for picking relatives and friends to top positions whenever it comes into power.”

Earlier, one of Nawaz's cousins, Hamza Shehbaz, had also served as chief minister in Punjab.

Nawaz thanked God during the ceremony and promised she would equally serve those who voted for her and those who didn't. “The doors of my heart and office will remain open for the opposition as well,” she said.

Nawaz's appointment was largely expected following the Feb. 8 parliamentary elections in which her father's Pakistan Muslim League party, or PML-N, emerged as the largest party in the National Assembly or lower house of the parliament and in the Punjab Assembly.

The PML-N, which was initially trailing candidates representing Khan's supporters — the former cricket player turned Islamist politician was barred from running — emerged last Friday as the largest single winner in the election after receiving 24 additional seats — 20 from out of the 60 seats reserved for women, as well as four seats out of 10 reserved for minorities. Nine independent members have also joined the PML-N.

The PML-N is now heading into a coalition with the Pakistan People’s Party, or PPP, with Nawaz's uncle, former Prime Minister Shehbaz Sharif, on a firm path to becoming the next prime minister, his second term in office.

The Sharifs are one of the top two families that have dominated Pakistani politics for decades. Nawaz Sharif, who served three times as a premier, was ousted from power in 2017 in a graft case. Khan, who replaced Sharif in 2018, granted him permission to travel to London for medical treatment following a court order.

Sharif came back to Pakistan from self-imposed exile abroad and returned to politics ahead of the elections. In her father's absence, Nawaz had led political campaigns and taken over his work.