Japan's cabinet on Friday approved a bill that will allow Emperor Akihito to hand over the Chrysanthemum Throne to his heir, Naruhito. The bill will make it possible to circumvent the imperial law that currently prevents the Emperor from abdicating.
The law has been sent to parliament, where the government hopes it will be approved without obstruction by mid-June.
If approved, this will be the first abdication of a Japanese emperor in 200 years, after Emperor Kokaku stepped down in 1817.
The government rushed to devise new legislation after Akihito, 83, suggested in a rare televised address last summer that he feared his age and declining health would leave him unable to perform official duties. But it has refused to make legal changes that would address the country's dearth of male heirs.
On Friday, Japanese media quoted officials as saying that Akihito would likely step down in December 2018, at the earliest, paving the way for his eldest son, Crown Prince Naruhito, to become the 126th occupant of the Chrysanthemum Throne.
The government believes that it is the ideal moment for the abdication as the Emperor turns 85 and completes three decades as head of state.
The bill has been designed specifically for Akihito in order to prevent future abdications, given the problems facing the imperial family regarding its succession line.
These problems were highlighted when Akihito's granddaughter, Princess Mako, 25, announced early this week that she plans to marry her college friend, which will result in the princess losing her royal status.
In addition to prohibiting abdication, the 1947 imperial law does not recognise the so-called collateral institutional branches, making female members of the royal family lose their royal status when marrying a commoner, which has since substantially reduced the number of members of the Japanese royal family.
Prime minister Shinzo Abe has resisted opposition pressure to include a clause allowing princesses to establish their own branches within the imperial family after they marry commoners – enabling them to take on their share of official duties and their sons to become emperors.
Under pressure from conservative supporters in his ruling Liberal Democratic party, Abe opposed the change, claiming it would create pressure to end the male-only succession law.
With Mako leaving the palace, the Japanese royal family, the world's oldest reigning hereditary dynasty, will be left with 18 members. Among those only three, apart from Akihito, are male with access to the throne: Crown Prince Naruhito, 57, his brother Akishino, 51, and Akishino's son Hisahito, 10, who is Princess Mako's younger brother.
Although abdication has been common throughout the history of the Chrysanthemum Throne and women were, in the past, eligible for the throne (the last one in the 18th century), the 1947 law allows only men to occupy the throne.