Campaigning for the leadership race of Japan's ruling Liberal Democratic Party (LDP) to choose Prime Minister Yoshihide Suga's successor officially began on Friday, with four veteran lawmakers competing for the top position.

The LDP election is set for September 29 and is being contested by former Foreign Minister Fumio Kishida, former Communications Minister Sanae Takaichi, Vaccination Minister Taro Kono and executive acting secretary-general of the LDP Seiko Noda, Xinhua news agency reported. The winner of the LDP race will become Prime Minister as the party controls the House of Representatives, the powerful lower chamber of parliament, since Suga has announced earlier this month that he would not seek re-election amid the public dissatisfaction with his Covid-19 response. Among the four candidates, Kono, 58, with his reform-minded policies, has been viewed as the early front-runner. He has gained backing from junior lawmakers with more vulnerable seats, and tops opinion polls on who should succeed Suga. Kono also won the backing of Shigeru Ishiba, former Defense Minister who decided to sit out of the race. Kishida, 64, is expected to gather supports from veteran lawmakers who are uncomfortable with Kono's reformist ideas, as well as to be backed by his own 47-member faction. Both Takaichi and Noda are aiming to become Japan's first female Prime Minister. Noda, 61, announced her bid on Thursday. Her late entry made it harder to predict who the eventual winner will be. Takaichi, 60, belongs to the LDP's right-leaning cohort and is closely allied with former Prime Minister Shinzo Abe. After campaigning, the LDP Diet members and rank-and-file members will cast their ballots on the election, and whoever secures a majority of votes will be declared winner.