Japanese Prime Minister Shinzo Abe’s ruling Liberal Democratic Party (LDP) is expected to win in Sunday’s upper house election, regaining the control it lost six years ago, as the opposition has fragmented.

In the first national election since political power changed hands in December, the LDP and its junior coalition partner, the New Komeito, stand to control a majority of 122 seats or more in the upper house, major polls showed.

The upper house has elections for half of its 242 seats every three years, and this year 433 candidates are competing for the 121 seats up for grabs. The ruling coalition is expected to win 63 or more of those seats, which they need for a majority.

“By winning a comfortable majority, we will build a self-respecting Japan under political stability,” said Abe, the seventh premier in as many years.

A weekend survey conducted by the Kyodo News agency showed 30.6 per cent of those polled said they would vote for the LDP, while support rate for the DPJ stood at 7.4 per cent and the New Komeito had 7 per cent.

“The LDP is expected to increase its seats in the upper house, however, the number of votes the party will gain may decline once again,” Akikazu Hashimoto, professor of political science at JF Oberlin University in Tokyo, said.

The premier appealed to voters to support his economic policies as he vowed to pull the world’s third-largest economy out of 15 years of deflation.

Since the start of the year, the benchmark Nikkei 225 Stock Average has jumped about 40 per cent and the yen has fallen 15 per cent against the dollar. The depreciation makes Japanese goods more competitive overseas and improves repatriated revenues.

But Hashimoto said Abe’s economic policies “have not helped improve people’s livelihood.” On Friday, the government said the ratio of non-regular workers, including part-time and contract workers, rose to a new record high of 38.2 per cent in 2012. Analysts said one of the most serious issues the country faces today is precarious employment, especially among women and young people.

Abe has also expressed eagerness to restart idled nuclear reactors and amend the nation’s pacifist Constitution.

All but two of Japan’s 50 reactors have been offline amid safety concerns following the 2011 nuclear disaster at the Fukushima Daiichi Nuclear Power Station, 250 kilometres north-east of Tokyo.

The plant suffered meltdowns at three of its six reactors after it was struck by the earthquake and tsunami.

Business leaders pressured the government to resume the operations of some reactors as power companies have faced mounting costs from fuel imports for thermal power stations.

A Kyodo survey showed that 50.6 cent of those polled said they were against the move, while 40 per cent supported it.