TOKYO - A six-member advisory panel holds its first meeting on Monday (Oct 17) to discuss a critical issue facing the Imperial system: Emperor Akihito's wish to abdicate in a few years' time due to his old age.

The issue is politically sensitive as Japan's post-war Constitution does not provide for the monarch's abdication. This means that the Imperial Household Law must be revised before Emperor Akihito can step down - a complicated process that could delay Prime Minister Shinzo Abe's plans to reform the country's pacifist Constitution to give its military a larger role.

Mr Abe appears to be trying to limit the scope of the panel's discussion to avoid any controversy over politically sensitive issues that could enrage conservative nationalists, his core supporters, the Japan Times reported.

The advisory panel, led by Mr Takashi Imai, honorary chairman of the Japan Business Federation or Keidanren, will hear opinions from constitutional scholars and historians.

None of the six are specialists in the history of the Imperial family and all are well known members of various government advisory panels, which are often criticised as being mere rubber stamps for plans by the government.

"The panel is a gimmick for the Prime Minister's Office to control the discussion" on Imperial succession, the Asahi Shimbun quoted an unnamed source close to Mr Abe as saying.

The discussions could drastically transform the future of the world's oldest royal system, which has a dearth of male heirs and faces concerns over the sustainability of the male-only succession line.

The 82-year-old emperor hinted in a rare televised address to the nation in August that he wished to step down. He currently has only five male heirs - a centenarian uncle, an 80-year-old brother, his two sons Crown Prince Naruhito and Prince Akishino, and a 10-year-old grandson.