TOKYO : Junichiro Koizumi, a maverick reformist who was one of Japan's most popular prime ministers in modern times, confirmed Thursday he had decided to retire from politics.

Koizumi, whose 2001-2006 tenure was the longest for a Japanese premier in three decades, told a meeting of supporters that he would not run in the next election, according to media reports quoting unnamed associates.

Koizumi, 66, known for his distinctive lion's mane of salt-and-pepper hair, confirmed the reports after being confronted by a horde of journalists in front of his office in his hometown of Yokosuka.

He deeply nodded twice without saying a word when asked, "Are you definitely retiring from politics?" according to footage broadcast by the public network NHK.

Jiji Press said Shinjiro, the second of Koizumi's three sons, would succeed him as a candidate for parliament representing Yokosuka, a naval hub on the mouth of Tokyo Bay that is home to a large US naval base.

Koizumi made the move just one day after Taro Aso, a conservative who has sometimes clashed with the reform-minded Koizumi, was installed as prime minister.

Koizumi had opposed Aso's bid to become prime minister by offering support in a ruling party vote to rival Yuriko Koike, who was seeking to become Japan's first female leader.

Koizumi, who still enjoys intense popularity, gained public support as he cast himself as a reformist fighting against entrenched interests within his own ruling Liberal Democratic Party (LDP).

He led the now struggling LDP to a landslide victory in the last general elections in 2005 which he cast as a referendum on his signature issue of breaking up the powerful post office monopoly.

Koizumi also forced banks to dump bad loans, a key step in Japan's economic recovery, and sent troops to Iraq -- a landmark step for a country that has been officially pacifist since the end of World War II.

Koizumi was one of US President George W. Bush's closest allies and paid two visits to arch-enemy North Korea to meet with leader Kim Jong-Il.

But Koizumi was deeply unpopular in China and South Korea. The two countries refused summits with him due to his visits to Tokyo's Yasukuni shrine, which honours Japanese war dead including war criminals.

Shortly before he stepped down as the prime minister, Koizumi visited US President George W. Bush and famously showed off his air guitar skills while singing Elvis Presley tunes at the rock star's Graceland Mansion.

Since leaving office, Koizumi has mostly stayed out of policy debates and indulged in his hobbies including going to the opera.

Koizumi's political handover to his son is commonplace in Japan. Eleven of the 18 members of Aso's new Cabinet had fathers or grandfathers who served in parliament.

- AFP/ir