TOKYO - The contest to choose a successor to Japanese Prime Minister Shigeru Ishiba as leader of the ruling Liberal Democratic Party (LDP) was gaining momentum, with multiple candidates officially entering the race this week.

Former economic security minister Takayuki Kobayashi held a press conference on Tuesday to outline his vision for party unity and economic growth, declaring his candidacy in the LDP leadership election.

Chief Cabinet Secretary Yoshimasa Hayashi also confirmed his intention to run, telling reporters at the National Diet that he felt compelled to lead the party.

Agriculture minister Shinjiro Koizumi expressed his intention to run earlier on Tuesday, stressing the need for party unity to tackle challenges such as rising prices.

Former economic security minister Sanae Takaichi was expected to announce her candidacy later this week.

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Meanwhile, former foreign minister Toshimitsu Motegi declared his candidacy last week.

The LDP leadership race, now less than a week from its formal announcement, was shaping up to be a crowded and competitive contest.

The LDP has decided to hold its leadership election in a full-scale format, including votes from both lawmakers and rank-and-file party members, on Oct 4.