TOKYO - The Liberal Democratic Party (LDP), Japan's national ruling party but the opposition in the Tokyo Metropolitan Assembly, wrested back the lead in a local election on Sunday (July 4).

But this was not enough for the party to secure a majority in the 127-seat assembly, together with its coalition partner Komeito, in Japan's most populous and prosperous prefecture.

Sunday's election, which put the spotlight on Covid-19 measures and the looming Olympic Games, is being closely watched, with local media framing it as a prelude to a general election that Prime Minister Yoshihide Suga must call by Oct 21.

The LDP was the second-largest party in the Tokyo Metropolitan Assembly, after a shock loss to Tomin First (Tokyoites First) in 2017. Tomin First was founded by Governor Yuriko Koike, who continues to serve as special adviser.

The LDP and Tomin First were neck and neck as results trickled in after voting closed at 8pm (7pm Singapore time), before the LDP pulled ahead with 33 seats to Tomin First's 31 seats.

Komeito won 23 seats, which gives the LDP-Komeito coalition 56 seats. This is short of the 64 seats required for a majority in the assembly.

The Tokyo election is significant, as the Japanese capital accounts for 11.1 per cent of the country's population and 19.5 per cent of gross domestic product.

The Olympics also remains controversial, as Covid-19 infections are again on the rise in Tokyo.

Mr Suga, who has strongly backed the Olympics, lost three national by-elections in a single day in April, and the tight race might not give him the confidence boost that he was hoping for.

"We have to examine where we fell short before heading into the House of Representatives election. We take this result seriously and will use it as fuel next time," said Mr Taimei Yamaguchi, the LDP's election strategy chief.

Meanwhile, Ms Koike, who was hospitalised for a week due to severe fatigue, has toned down her backing for Tomin First candidates, in what experts see as a bid to mend fences with the LDP.

All eyes in Nagatacho, Japan's political nerve centre, are watching Ms Koike's moves amid talk that she is trying to pave a return to national politics, four years after she broke away to found Tomin First.

But rather than overtly rally for Tomin First candidates in this election, she had instead been cryptically talking about an "all-Tokyo approach against Covid-19" and her support for "reform-minded candidates".

Adding to talk on the grapevine are Ms Koike's frequent meetings with LDP secretary-general Toshihiro Nikai, an influential kingmaker and political power broker.

There were 271 candidates vying for 127 seats in Sunday's election.

Tomin First held 45 seats, while the LDP had 25 and Komeito 23 in the last assembly. The Constitutional Democratic Party of Japan (CDP), which is the main national opposition, held eight seats, while the Japanese Communist Party (JCP) held 18 seats.

Tomin First's losses on Sunday will not affect Ms Koike's standing as governor, for which she was re-elected last year for a four-year term ending 2024.

The opposition made gains, with the CDP winning 15 seats and the JCP, 19. Both parties had campaigned for the Olympics to be postponed or cancelled, and had coordinated to field candidates to avoid a split vote.

Sophia University political scientist Koichi Nakano, noting that pollsters had expected a more clear-cut LDP victory, said that the LDP "seems to have failed to make the most of the opportunity of the falling star of Tomin First".

"This was quite a confusing contest and it seems people had a hard time choosing between the LDP and Tomin First, which is like a Koike offshoot that she seems to have half-abandoned," he said.

He does not, however, see a comeback by Ms Koike to national politics as realistic.

He said: "She may be somewhat more popular than Mr Suga but she's also tainted by Covid-19 policies and the decision to go ahead with the Olympics. It is a rather far-fetched idea that she will be accepted as LDP president and she will not want to go back to become a foot soldier again."

Voter turnout was 42.4 per cent, down 8.9 percentage points from the 51.3 per cent in 2017 when Tomin First rode on what has been called the "Koike whirlwind" to victory.