The establishment candidate backed by Prime Minister Shinzo Abe romped home in Sunday's election for governor of Tokyo in a result which analysts said would boost the premier's pro-nuclear agenda.

The poll for chief executive of one of the world's biggest cities had been seen as a referendum on atomic power in a country still scarred by the 2011 Fukushima disaster.

But livelihood issues appeared to play a bigger role in the election, which saw an emphatic victory by Yoichi Masuzoe -- a former television pundit and one-time cabinet minister.

Only around a third of eligible voters cast their ballots, media reported, down about 10 percentage points on the last election.

The city's 13 million inhabitants had been hit with the heaviest snowfall in nearly half a century on Saturday. Despite a rapid thaw on polling day, many streets remained treacherous.

"I want to make Tokyo the number one city of the world, in areas including disaster prevention, welfare and the economy," Masuzoe told reporters as the scale of his victory became apparent.

"And above all, I will make the 2020 Olympic and Paralympic Games successful."

Even if nuclear power was not a decisive election issue, Koichi Nakano, professor of political science at Tokyo's Sophia University, said Masuzoe's win would give Abe a fillip and strengthen his hand on nuclear matters.

"The anti-nuclear agenda is a very difficult one to achieve," he said.

The vote had been triggered by the resignation of the previous governor, a policy wonk who admitted to political naivite after accepting an undeclared 50 million yen ($500,000) from a scandal-mired hospital magnate.

None of the major political parties had fielded a candidate, but all had swung behind one of the bigger players. Abe's conservative Liberal Democratic Party backed Masuzoe even though he left the party a few years ago.

Like Abe, he has said that Japan needs to switch its nuclear reactors back on. All of them are idled at present amid public nervousness in a country badly scarred by the disaster at Fukushima.

Opinion polls show a significant number of Japanese oppose nuclear power, but the two main anti-atomic candidates failed to gain enough traction to overturn Masuzoe's determined drive to talk about bread-and-butter issues like the economy and welfare.

Former prime minister Morihiro Hosokawa, 76, did not manage to connect with voters despite having the high-profile backing of popular ex-premier Junichiro Koizumi.

"I could not get the anti-nuclear issue at the centre of the campaign," Hosokawa told reporters.

Exit polls by major media showed he had been pushed into third place by renowned lawyer Kenji Utsunomiya, 67, who was also firmly anti-nuclear.

Pundits had suggested that a big vote for the two of them, even if Masuzoe won, would make life more difficult for Abe in his drive to get Japan's nuclear reactors back on line.

"I voted for Hosokawa because I think the most important thing today is to get rid of nuclear," Shu Ohara, 35, told AFP outside a polling station.

Robert Dujarric, director of the Institute of Contemporary Asian Studies at Temple University in Tokyo, said the game might not be up yet for those who want an end to nuclear power in Japan.

"It's not the end of the anti-nuclear movement because Tokyo doesn't have nuclear reactors. The key is what residents of areas with nuclear power plants think," he told AFP.

But many voters had more immediate concerns.

A 72-year-old woman said she voted for Masuzoe because he appeared to care more about the plight of the elderly.

"It's scary to see the balance in my bankbook falling," she said as she left a polling station.

"I tried to resume working some time ago but was told (by a Tokyo city official) that it would deprive young people of jobs," the discontented pensioner told AFP.

Like the rest of Japan, Tokyo must provide affordable care for the growing number of elderly, but balance that with maintaining its appeal to the younger generation who make it a vibrant commercial and cultural hub.

Between 2007 and 2009 Masuzoe served as health, labour and welfare minister, initially under Abe's first short-lived, administration.

The governor of Tokyo presides over Japan's most populated and wealthiest prefecture. Its annual 13-trillion-yen ($130 billion) budget rivals that of Sweden and it has 165,000 people on its payroll.

Masuzoe's in-tray will be filled with preparations for the 2020 Olympics, with huge construction projects and the renovation of the city's ageing infrastructure already under way.