The central role that Shinto, Japan's indigenous religion, will play in Friday's funeral of Emperor Hirohito has driven the 2,000-year-old faith into a storm of controversy.

Critics say conducting a Shinto funeral for Hirohito is an attempt to revive a cult religion which has close associations in Japan with nationalism and wartime aggression.Supporters maintain Shinto is an irrevocable part of Japanese tradition.

"It is actually not only a religion but a way of life, the quintessential spirit of the Japanese, if you like," said Kazufumi Sano, chief secretary of the Institute for Shinto Studies.

Yet it is religion that has ignited controversy over the funeral, arrangements for which are designed not only to demonstrate national mourning but also Japan's new international status.

Political and royal dignitaries from more than 150 countries, including President Bush, the king of Spain and President Francois Mitterrand of France, are scheduled to attend the last rites for Hirohito, who died January 7 at the age of 87.

"I'd hate to see the whole world watch a national funeral that's Shintoist," said Hideo Fukada, a Christian missionary. "It fails to convey the fact that we have freedom of religion here."

In an effort to please both traditionalists and critics, Japan has divided the funeral rites into two parts.

They will start with a private Shinto service, conducted by Shinto priests, attended by the Imperial family and some Japanese dignitaries such as Prime Minister Noboru Takeshita.

An official state ceremony, free of religious overtones, is to follow.

Some say the distinction is not enough and that Shintoist tendencies should be completely purged from the funeral. Representatives of the Japan Socialist Party have refused to attend the first part of the ceremony.

Isao Sato, a legal scholar who helped frame Japan's post-war constitution, said the government had already "trod a very fine line of separation" of church and state in the arrangements for ceremonies following Hirohito's death.

"I believe the constitution calls for as much separation as possible of church and state in state funerals," Sato said.

According to Japan's 1947 constitution, which denounces militarism, the Emperor is a "symbol of the unity of the Japanese people" and not a religious or a sovereign figure. But he remains at the apex of the Shinto faith, which contends that Japan was founded by gods and the emperors descended from the Sun Goddess.

"Shinto gave a religious basis for Japanese ultra-nationalism, ultra-militarism," Sato said.

"The Emperor's so-called divine status is defined by Shinto. So, although he was stripped of divinity after the war, the Shinto connection cannot be wiped out," said Takeshi Umehara, Director of the International Research Center of Japanese Culture.