Former Japanese prime minister's effort to end nuclear power riles party

In the years after he stepped down as prime minister of Japan in September 2006 and then left the political arena in 2009, Junichiro Koizumi was apparently happy to remain in the shadows.

But the hugely popular Koizumi has decisively stepped back into the spotlight to demand that the government phase out nuclear power.

And such a high-profile figure breaking rank with his Liberal Democratic Party's official line on nuclear power has caused concern in Tokyo's halls of power.

After visiting nuclear facilities in Finland and Germany - which has committed to closing down all its nuclear plants by 2022 - Koizumi said his belief that Japan should get rid of its nuclear reactors had only been reinforced.

His comments were initially ignored by the media, until he began to repeat them in media interviews and then, on October 20, he invited reporters to a lecture during which he was strongly critical of the government's vow to restart the nation's mothballed reactors. His condemnations of the country's official policy made headlines the next day and have continued to do so in the nation's media since then.

Unable to overlook the attention-grabbing debate that his charismatic predecessor had been provoking any longer, Prime Minister Shinzo Abe said Koizumi's proposals were "irresponsible", while another minister said Koizumi was clearly not thinking about what he was saying.