TOKYO - JAPAN opposition leader Ichiro Ozawa, who has struggled to portray himself as physically fit to be prime minister, has checked into hospital for several days with a bad cold, his party said on Tuesday.

Mr Ozawa, 66, who has a history of health problems, went to a Tokyo hospital late Monday after his voice grew so hoarse he had trouble speaking.

'I presume he's taking two or three days off as a break,' Mr Yukio Hatoyama, the secretary general of Mr Ozawa's Democratic Party of Japan (DPJ), told reporters with general elections expected soon.

The DPJ declined to provide more details but Jiji Press reported that Mr Ozawa was receiving fluid from a drip.

In recent days, Mr Ozawa has been seen at party meetings wearing a scarf and a small mask over his mouth and reportedly complained that he could barely speak.

A former heavy smoker, Mr Ozawa was hospitalised for 10 days last year due to fears of a relapse of a heart ailment.

The DPJ is hoping for a landmark victory in upcoming elections against the ruling Liberal Democratic Party, which has been in power for all but 10 months since 1955 but has gone through four prime ministers in the past two years.

Newspaper polls show that the DPJ has taken a narrow lead in voter preferences.

But Mr Ozawa lags far behind his rival Prime Minister Taro Aso as the public's choice to be the next leader.

Mr Ozawa, a former ruling party stalwart who defected in 1993, has a rough public image and won the nickname 'The Destroyer' for his passion for battles in parliament.

Last week he presented to parliament an outline of a DPJ-led government, promising to fix Japan's ailing pension system, close the widening gap between rich and poor, and curb the powerful bureaucracy.

Mr Aso took office on September 24 with a mission to lead his party into elections. But Mr Aso, whose government has struggled in early opinion polls, said on Monday he would not call snap polls immediately.

The health-conscious Aso, who jogs regularly at age 68, appeared in parliament on Tuesday, where he pressed the opposition on his demands for an extra budget to help revive the struggling economy.

Mr Katsuya Okada, a DPJ executive member, told Mr Aso to call a snap general election swiftly after pushing through an economic package.

'Public sentiment is demanding that the government implement economic measures before anything else,' he said.

'It would be the right way for the government to answer people's demands first and then dissolve the lower house.'

Mr Aso is also pushing to extend a domestically unpopular naval mission providing support in the Indian Ocean to the US-led 'war on terror' in Afghanistan.

The DPJ briefly forced a halt to the naval mission last year, arguing that officially pacifist Japan should not be part of 'American wars'.

The opposition has said Mr Aso should call a snap election before taking up discussion on the naval mission. -- AFP