TOKYO >> Tokyo residents were voting for the city’s assembly in an election Sunday that could alter national politics as a populist governor aims to strengthen her base and challenge Prime Minister Shinzo Abe’s scandal-laden ruling party.

At stake are 127 assembly seats. Opinion polls have predicted a sweeping victory for Gov. Yuriko Koike’s new party, Tomin First no Kai, or Tokyoites First party, as Abe’s Liberal Democrats have taken a hit after being buffeted by scandals and gaffes.

The Liberal Democrats, who are just short of a majority in the Tokyo assembly, have fielded 60 candidates against the Koike party’s 50.

The result of the Tokyo election has in the past set the tone for national polls. Koike is rumored to be eyeing a return to parliament to run for prime minister.

A former TV newscaster, Koike became the first female leader of Japan’s capital last summer and earned a reformist image after repeatedly clashing with the male-dominated city government. She portrayed the LDP-dominated assembly as a place of murky politics run by an anti-reform old boys’ club which is interfering with her agenda, including cost-cutting of the 2020 Tokyo Olympics. She has approval ratings of about 60 percent.

Koike, 64, had shifted parties until settling with the LDP in 2002 and since held key party and Cabinet posts including defense minister. She angered party seniors when she abruptly ran for Tokyo’s governor last year, but had never officially left the party until last month to head her own. She keeps friendly relations with Abe, prompting speculation she may eventually run for his job.

Abe had long enjoyed stable approval ratings since taking office in 2012, but he and his party have been hit by a series of scandals in recent months.

Most recently, Defense Minister Tomomi Inada was grilled over her questionable remark at an election rally for a local LDP candidate when she asked for support from her ministry and the Self-Defense Force, which was seen as violating laws stipulating neutrality of civil servants and the military.

Abe is also embroiled in his own scandal, in which he is alleged to have influenced an approval of a school run by his friend. He has repeatedly denied the allegations but refused to provide further explanation in parliament.

Throughout the Tokyo assembly election campaign, Abe stayed behind the scenes reportedly out of concern his presence would not help the party image. On Saturday, when he made his first appearance during a street rally, he faced a big crowd yelling “Step down Abe!”