Japan's Prince Akishino says a highly religious ritual that is part of next year's succession ceremonies should be paid for privately by the Imperial family, questioning the Government's decision to use public money.

Key points: Prince Akishino argues the constitutional separation of religion and state means the Royal family should pay

Prince Akishino argues the constitutional separation of religion and state means the Royal family should pay Japan's Government insists on following previous examples and paying for the ceremony

Japan's Government insists on following previous examples and paying for the ceremony The Government also wants the Royal family to take a more "authoritative" role

Emperor Akihito's younger son spoke about the contentious issue in a news conference recorded for his 53rd birthday on Friday.

Emperor Akihito plans to abdicate next year and will be succeeded by Crown Prince Naruhito.

Prince Akishino would then become first in line of succession.

Prince Akishino said using public funds for the Daijosai, the first communion that the new emperor performs with Shinto gods, is questionable since Japan's constitution separates religion and state.

The ritual is expected to be held in mid-November next year, and the Government has announced it would cover the cost, following the precedent set at the time of Emperor Akihito's succession 30 years ago.

The cost of that rite alone was 2.25 billion yen ($27 million), though the Government is expected to spend slightly less next year.

The Palace budget this year for the Imperial family's private activities, including religious ones, is about one-seventh of that amount, and Prince Akishino said the ceremony could be scaled down to reduce its cost.

"It's a Royal family event, and it is highly religious," Prince Akishino told reporters.

"The question is if it is appropriate to use government funds to cover the cost of such a highly religious event."

He added the ritual held for his father should not have been funded by the government.

The Government has already decided to follow the previous example, he said.

"Personally, I still feel awkward … I still believe [the ritual] should be covered by the Imperial family budget."

He said he conveyed his views about the upcoming event to Palace officials, but they "would not listen to me".

Emperor Akihito plans to abdicate next year and will be succeeded by Crown Prince Naruhito. ( AP/Imperial Household Agency of Japan )

The constitutionality of government funding of the Daijosai ritual has long split legal experts and public opinion.

Chief cabinet secretary Yoshihide Suga said on Friday there would be no change in the government decision to fund the ritual.

The Government, after an examination by a panel of experts, concluded the rite was too religious to be considered an official duty of the Emperor but was a key part of the succession ceremony and therefore deserves government funding.

The Prince's rare expression of views opposing the Government's position topped Japanese newspapers and television talk shows on Friday.

They also highlighted the contrast between the conservative and hawkish stance of Prime Minister Shinzo Abe's Government and the Imperial family's views, seen as liberal and pacifist.

"Differences of views between the conservatives and the Royal family are quite significant," Hideya Kawanishi, a Nagoya University historian and expert on Japan's monarchy, said recently.

Japanese Government wants 'authoritative' Emperor

While Mr Abe has pushed to expand Japan's military role and stopped apologising to Asian victims of World War II since taking office six years ago, the Emperor has stepped up his expressions of remorse over Japan's wartime actions, and he and his two sons have repeatedly expressed their support for the

country's pacifist constitution.

"What [Prince Akishino] said makes sense," Sota Kimura, a liberal-leaning expert on the constitution, told NHK public television.

"The Government should have studied how to carry out the ritual next year rather than merely following the previous example."

But Hidetsugu Yagi, a constitutional scholar and adviser to the Prime Minister, criticised Prince Akishino, calling his comments about the Government's budget decision "political" interference.

Members of the Japanese Royal family rarely speak out about their views, in part because the Emperor was stripped of political power after Japan's defeat in World War II, which was fought in the name of Emperor Akihito's father, Hirohito, when he was revered as god.

Hirohito renounced that status and the Emperor's position become symbolic under the post-war constitution.

Mr Abe's ruling party and his Government want the Emperor to be a more authoritative figure.

The Government and his supporters are campaigning for constitutional revisions that would restore Japan's pre-war paternalistic social values under the Imperial family.

AP