Attorney-General Nicola Roxon and Senator Chris Evans are to resign from their ministerial positions in the Australian government.
Prime Minister Julia Gillard announced their resignations in Canberra on Saturday, three days after she set 14 September as the date for the next federal election.
"Two of my most senior and valued colleagues ... are stepping down from their ministerial roles and in the case of Chris Evans from the senate leadership as well."
Ms Gillard said they first raised their futures with her a year ago.
Senator Evans said he would also step down from the Senate in a few months when a suitable replacement could be found.
He had been talking to the prime minister about a planned departure for some time.
"I didn't want to serve following the next election," he said.
Senator Evans said it had been a tremendous honour to be part of the Labor government and he had even been acting prime minister for a few days - and "nothing went terribly wrong" in that time.
AAP reports a ballot to replace him as Senate leader will be held at a caucus meeting on Monday.
Senator Evans was first elected to the Senate in 1993.
Ms Roxon has been in Parliament since 1998. She will move to the backbench until the election then leave politics, creating a vacancy in the seat of Gellibrand, Melbourne.
"It is time to move on and I have reached that point," she said on Saturday.
She said that if she contested the next election, her daughter would be in high school by the time her term ended.
Victorian MP Mark Dreyfus will be promoted to become attorney-general.