TOKYO (AFP) - Tokyo voters appeared to give their support to the economic policies of Japanese Prime Minister Shinzo Abe on Sunday, with his party winning a landslide victory in local elections in the capital.

Voting for the 127-seat Tokyo Metropolitan Assembly was widely being seen as an indicator of public opinion in the run up to national upper house polls expected on July 21.

And results from public broadcaster NHK and other media outlets showed Abe's Liberal Democratic Party was set to win 59 seats alone, or 82 with the help of its centrist government ally the New Komeito party.

"We thank the voters. I want this victory to carry on to the next elections," LDP secretary general Shigeru Ishiba said on television.

Turnout in the city of 13 million was low, at 43.42 per cent, down more than 11 percentage points compared to the previous election in 2009.

Mr Abe said he regretted the low turnout and while welcoming the victory he said "many people have not yet felt the effects of our policies on the economic situation".

The prime minister had himself described the election as a "win-at-all-costs" battle, knowing the vote would be seen as a dress rehearsal for the Senate in July.

If Mr Abe can secure control of the upper house, it will relieve a legislative bottleneck and give him free rein to push through the painful reforms commentators say Japan desperately needs.

It was the first voters' verdict on Mr Abe's administration, which came to power in December and still enjoys approval ratings of more than 60 per cent.

An economic policy blitz dubbed "Abenomics", which blends massive monetary easing, big fiscal spending and a series of reforms aimed at freeing up businesses, has dominated the opening months of the Abe government.

Japan's sleep-walking economy - the world's third largest - has been given a jolt by the moves, with the yen shedding some of its export-sapping strength and the stock market putting in the best performance in the developed world this year.

Despite a few weeks of wobbles that have seen the headline Nikkei 225 index lose some of its steam, many economists still feel Abenomics has legs.

Detractors warn that with a majority in both houses, Mr Abe will take his eye off the economic ball and push the conservative social agenda he was known for before the election, including a possible reassessment of Japan's wartime history.

They say this risks further irritating already inflamed relationships with China and South Korea.

The campaign in the Japanese capital had been relatively low key, with few issues of contention for Tokyo voters.

The LDP's main opponents, the Democratic Party of Japan, were the largest grouping in the assembly before the election, but were in disarray after their national drubbing last December.

Tokyo governor Naoki Inose, in whom the bulk of city power is vested, was not up for election, having won a four-year term in December.