Q&A: Japan's upper house poll

Shinzo Abe's popularity has plummeted in the last 10 months

Voters in Japan are going to the polls on Sunday for upper house elections that could see Prime Minister Shinzo Abe forced from office.

What are the polls for?

Half of the 242 seats in Japan's House of Councillors, or upper house, are being contested.

Mr Abe's Liberal Democratic Party-led ruling coalition currently controls 132 seats. They need to win 64 of the seats that are up for grabs in order to retain their majority.

Why is the election important?

This is the first electoral test for Mr Abe since he took office in September 2006.

Support for his administration has plummeted in recent months and Mr Abe has admitted he faces a tough battle to retain his upper house majority.

The ruling coalition has a sizeable majority in the House of Representatives, or lower house. And a bad result in upper house polls would not have direct implications for Mr Abe, because the house does not choose the prime minister.

But upper house elections are often seen as a referendum on the ruling party, and voters look likely to deliver a fairly grim verdict on Mr Abe's first 10 months in office.

Some experts say he may feel that he has to take responsibility for a poor showing in the polls and step down from office.

Why is Mr Abe in trouble?

He went into his premiership with solid popular support and soon orchestrated high-level reconciliation with China.

But his administration has been severely dented by a series of ministerial gaffes and scandals. Two of his ministers have been forced to resign and one committed suicide.

The most significant factor, however, has been a nationwide pensions debacle, with a government agency admitting it has lost records relating to millions of payments.

Pensions are a key issue in Japan's greying society and, although the mistake was not made under Mr Abe's leadership, many voters have started questioning his skills in the job.

What is his party saying?

LDP stalwarts say Mr Abe's premiership is not in danger. Both LDP policy chief Shoichi Nakagawa and chief government spokesman Yasuhisa Shiozaki have emphasised that this election is not about the prime minister.

"Elections for the upper house are not seen as occasions to choose an administration," Mr Shiozaki said earlier this week.

And Mr Abe has also hinted he hopes to stay put. "No matter what the situation, I am determined to fulfil my mission of keeping reforms moving forward steadily," he wrote is his weekly e-mail magazine.

Yet there is a precedent for resignation - Prime Minister Ryutaro Hashimoto stepped down after the LDP was defeated in upper house elections in 1998.

What about the opposition?

The main opposition party, the Democratic Party of Japan (DPJ), was humbled in the last general election in September 2005, but under Ichiro Ozawa it has rebounded somewhat.

According to some polls, Mr Ozawa is now perceived as a stronger leader than Mr Abe. Nonetheless, the fact that Mr Abe is in trouble is perhaps less to do with DPJ policies than with voters' perceptions of government failings.

Mr Ozawa has said that if the DPJ, together with other minor opposition parties, fails to secure an upper house majority, he will resign.