Japan's ruling Liberal Democratic Party on Tuesday officially started its campaign for a new leader, with three candidates making their pitches, and the winner will have to confront a steep economic recession.

Despite the fact that key heavyweights of the LDP have already stacked the deck in favor of outgoing Prime Minister Shino Abe's top aide Yoshihide Suga, two other candidates remained unmoved about pulling out of the race on Tuesday. They are Shigeru Ishiba, 63, a former defense minister and a vocal critic of Abe, and Fumio Kishida, 63, a former foreign minister and currently the LDP's policy chief. Suga, 71, has been Japan's chief Cabinet secretary for nearly eight years.

The race began after Abe announced his intention to step down due to health concerns. The winner is set to become Japan's next prime minister given the party's dominance in the parliament, known as the Diet.

A leadership election will be held next Monday, according to the LDP, and the new prime minister is expected to be installed at an extraordinary Diet session to be convened on Sept 16.

At a joint media conference at the LDP's headquarters in Tokyo, Suga reiterated his vow to carry on Abe's policies.

He called for eliminating sectionalism at ministries and creating a digital agency to facilitate online technology usage to counter the impact of the COVID-19 pandemic.

Bellwether for next race

While Suga has secured the backing of the majority of the 394 LDP lawmakers who will vote, the focus of the election is also on how many votes Ishiba and Kishida can attract from the 141 votes cast by three delegates each from the party's 47 prefectural chapters. The leadership election is also regarded as a bellwether for the next party leadership election, to be held in September next year.

On Tuesday, Ishiba was seeking a departure from Abe's policies, saying he wants to reset Japan and "rewrite its blueprint". "Otherwise, our country won't be able to survive the next era," Ishiba said.

While praising Abe for his achievements on the economic and diplomatic fronts, Kishida said he will address the income gap in Japan and pledged to raise the minimum wage and reduce education costs.

"I will listen carefully, and turn the voices of the masses into political energy. Disparity and division have been growing in Japan and around the world. I will tackle this issue and foster cooperation," Kishida said.

Whoever becomes the next prime minister of Japan, a daunting task for him will be how to handle the deep economic recession. Tuesday's revised gross domestic product data showed that the world's third-largest economy shrank an annualized 28.1 percent over April-June, more than a preliminary 27.8 percent contraction.

Other data also put that challenge in perspective with household spending and wages falling in July as the impact of the pandemic kept consumption frail even after lockdown measures were lifted in May.

"The new administration will have to take additional steps to help households as the effect of measures taken so far have been largely diluted," said Erbiao Dai, vice-president of the Asian Growth Research Institute in Fukuoka.

Agencies contributed to this story.