Japan will have a new prime minister by early next week, a cabinet minister has said.
Prime Minister Naoto Kan has faced demands to step down amid criticism of his handling of the March 11 earthquake and tsunami and subsequent nuclear crisis.
Economy minister Kaoru Yosano said Mr Kan told cabinet members that his days are numbered and they should be ready to resign en masse next Tuesday.
On Friday, parliament is set to pass two key bills which Mr Kan wanted to see through.
Polls show Mr Kan's approval rating has fallen below 20%. Critics accuse him of a lack of leadership and survivors have complained of slow relief efforts.
Former foreign minister Seiji Maehara is favourite to take over. He is set to join the party leadership race on Monday.