Legislators from ousted Pakistani Prime Minister Imran Khan's party announced they are resigning en masse from the lower house of parliament on Monday in protest against the formation of a new government.

"We are announcing we are all resigning," Shah Mahmood Qureshi, former foreign minister and vice president of Khan's party, said in a speech in the assembly ahead of the vote to elect a new prime minister.

Khan was ousted in a no-confidence vote by the same assembly in the early hours of Sunday.

Qureshi was previously named by Khan's Pakistan Tehreek-e-Insaf (PTI) party as a candidate for the election of a new prime minister, in a contest with opposition leader Shehbaz Sharif.

(With input from Reuters)