Two major factions of the ruling Liberal Democratic Party, including one led by Finance Minister Taro Aso, were set to support Chief Cabinet Secretary Yoshihide Suga in a vote to pick the successor to outgoing Prime Minister Shinzo Abe, sources familiar with the matter said Monday.

Suga, the government's top spokesman, has indicated he will stand in the elections, sources said. He is expected to announce his candidacy in the LDP leadership race after the party formally decides on Tuesday to hold the election on Sept. 14.

Aso, a longtime Abe ally, who himself held the top slot from 2008 to 2009, has said he will not seek a second turn in power, saying he would throw the support of his 54-member faction behind whoever can best implement policies that align with his thinking.