TOKYO (Reuters) - Japan’s struggling opposition Democratic Party elected former foreign minister Seiji Maehara to lead the party on Friday as it tries to raise its single-digit ratings and fend off a challenge by a new group with ties to popular Tokyo Governor Yuriko Koike.

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Maehara, 55, a conservative on security who shares Prime Minister Shinzo Abe’s desire to revise the post-war, pacifist constitution, takes over amid speculation that Abe may call a snap general election later this year to refresh his mandate.

Maehara previously held the Democrats’ top post from 2005-2006.

“If I were to refer now to a change in government, the people would say, ‘Whatever are you talking about?’ But we must change this dangerous political situation where there are no choices except the (ruling) Liberal Democratic Party or hopes for something whose form is not yet known,” Maehara told his fellow party members.

The party, an often fractious mix of conservatives and liberals, had to pick a new chief after its first female head, Renho, who goes by one name, quit having failed to capitalize on Abe’s sagging ratings, eroded by suspected cronyism scandals and a perception he was complacent after 4-1/2 years in office.

Abe’s support has since rebounded off lows of under 30 percent in some polls, touching 46 percent in a survey by Nikkei business daily in late August.

The novice Democratic Party surged to power in 2009, ousting the long-ruling LDP with promises to put individuals ahead of companies and address social inequalities.

But many voters still have bad memories of its rule, which was plagued by infighting, policy flip-flops and unkept promises. Abe led the LDP to a huge victory in December 2012.

The Democrats could face a new threat if efforts by backers of former LDP lawmaker Koike to create a new nationwide opposition party bear fruit.

Her Tokyo Citizens First party dealt the LDP a historic defeat in a metropolitan assembly election last month, spurring talk it could evolve into a “Japan First” party to field candidates in a general election that must be held by late 2018.

Speculation is simmering that Abe could call a snap election as early as October, to take advantage of opposition disarray, though he’d risk losing the ruling bloc’s “super majority” in the lower house.

Maehara defeated liberal rival Yukio Edano, a former chief cabinet secretary during the Democrats’ days in power.