The Japanese government has approved a one-off bill that allows ageing Emperor Akihito to step down from the Chrysanthemum Throne in what would be the first such abdication in two centuries.

Prime Minister Shinzo Abe's cabinet signed off on the legislation on Friday, Chief Cabinet Secretary Yoshihide Suga told reporters.

The bill will now be sent to parliament, where it is expected to pass.

"The government hopes for the smooth passage of the legislation," Suga said.

Reports of the 83-year-old Akihito's desire to retire surprised Japan when they emerged July 2016.

"When the emperor first hinted that we might think about his abdication, most people were shocked because we were not prepared to hear that, but now many Japanese people support his idea," Yoshiki Mine, president of Institute for Peaceful Diplomacy in Tokyo, told Al Jazeera.

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Akihito, who has had heart surgery and prostate cancer treatment, said in rare public remarks last year he feared age might make it hard for him to fulfil his duties.

But current Japanese law has no provision for abdication, thus requiring politicians to craft legislation to make it possible.

The bill is one-off legislation that would allow only Akihito to step down, with no provisions for future emperors, but Mine said he believed it could serve as a sort of precendent

It also makes no reference to the controversial issue of changing the system to allow women to inherit the throne, or to stay in the imperial family upon marriage, Japanese media said, although political parties are discussing a separate resolution on the topic.

"The bill is a certain kind of compromise between the more orthodox and conservative thinkings and the awareness of the new situation," Mine said.

A change in the system has been suggested as a way to deal with a shortage of male heirs and a shrinking pool of royals, a problem thrust back into the limelight this week with news that Akihito's eldest granddaughter will marry a commoner, after which she must leave the royal family.

There are only four heirs in the line of succession - Akihito's two middle-aged sons, Akihito's brother, and Hisahito, the 10-year-old son of Akihito's younger son.

The status of the emperor is highly sensitive in Japan given its 20th century history of war waged in the name of Akihito's father Hirohito, who died in 1989.



An abdication is not expected until at least the end of 2018, according to reports.