Japan's chief cabinet secretary Yoshihide Suga on Tuesday cemented his status as the clear frontrunner in the race to become the country's next prime minister, ahead of a vote expected on September 14.
Suga has yet to officially announce he is running for the top job, after Prime Minister Shinzo Abe said last week he would resign over health problems.
READ MORE: Japan PM Abe Shinzo announces he will resign over health problems
But he has nonetheless already become the favourite, with the largest faction within the ruling Liberal Democratic Party throwing its support behind him on Tuesday, local media said.
Two other key factions have also said they will back Suga, who is set to make his candidacy official on Wednesday, when the LDP is expected to confirm the election date.
Local media said candidates will be required to register their run on September 8 -- with campaigning beginning immediately after.
Two candidates, former defence minister Shigeru Ishiba and LDP policy chief Fumio Kishida, have so far officially announced plans to stand.
The LDP election is for the party leadership, with a parliamentary vote for prime minister following on September 16, reports said. Opposition candidates are expected to stand, but the vote is seen largely as a formality that will endorse the ruling party's choice.
A leadership contest would usually poll ruling-party lawmakers and LDP members nationwide. But the LDP has opted for a constrained format, polling only its MPs and three representatives from each of the country's 47 prefectures.
The decision has elicited some criticism, but party officials said it would take too long to organise a broader vote.
"The prime minister is sick, his illness has re-emerged. He is working hard under very difficult conditions," Shunichi Suzuki, chairman of the party's general council, told reporters on Tuesday.
"If we were to hold a full-scale election, it would take two months. With the prime minister's health, two months is very long. We can't take that long," he said.
Three main candidates
While several candidates have emerged for the race, Suga appears to have built an insurmountable support base within the party.
The 71-year-old has held his powerful post for years -- coordinating policy among ministries and agencies, and serving as the effective face of the government as its chief spokesman.
Considered a pragmatist without strong ideological positions, he is a close Abe advisor who encouraged the prime minister to run again after a disastrous first term in office ended after just a year in 2007.
Former defence minister Ishiba, who announced his run on Tuesday, polls well with the general public but is less popular among party members.
Ishiba once left the LDP -- spending time as both an independent and briefly joining another party -- and many within the ruling bloc have not forgiven the political dalliance.
LDP policy chief Kishida, a former foreign minister, became the first candidate to jump into the race earlier Tuesday.
He had often been described as Abe's favoured successor, but the outgoing prime minister has said he will not endorse a candidate, and Kishida's limited public profile may pose a problem as he launches a challenge to the likes of Suga.
Abe announced his shock decision to step down on August 28, explaining he was suffering a recurrence of ulcerative colitis, a condition that has plagued him for years.
He is Japan's longest-serving prime minister, but has seen his government's approval ratings sink in recent months with the public unimpressed by his handling of the coronavirus outbreak.
His successor will face a raft of challenges, from the pandemic to a sinking economy, as well as the task of ensuring the postponed Tokyo 2020 Olympic Games can go ahead next year.