Kickbacks paid by Japanese companies in the Philippines during the rule of Ferdinand Marcos are shaping up as a political challenge to the ruling Liberal Democratic Party, despite promises from Prime Minister Yasuhiro Nakasone for a full account of the payments.

The Socialists, the leading opposition group in the parliament, are pushing for special hearings later this month before a budget committee, with testimony by executives from the companies involved. They also have announced formation of a special party panel to pursue the issue, perhaps to the point of sending a delegation to Manila.

The three other major opposition parties, Komeito (Clean Government Party), the Communists and the Democratic Socialists, meanwhile, announced plans for investigations of their own.

Opposition parties have attacked the ruling party over misuse of aid for years. Chisato Tatebayashi, a Socialist Party official, said his group also hopes to find out whether Japanese politicians received money from abroad.

Praising the release by the United States of documents suggesting that Marcos made illegal contributions to U.S. political campaigns in 1980, Tatebayashi said, "in Japan that side has not yet been made clear."

Unconfirmed reports from Manila over the weekend said that in 1972 Marcos made more than $500,000 in political contributions to the then Japanese prime minister, Kakuei Tanaka.

Tanaka was convicted in 1983 of accepting 500 million yen, about $2.9 million, from the Lockheed Corp. to assist the sale of its airliners in Japan.

Today, the Japanese Foreign Ministry provided a Diet committee with copies of documents provided by U.S. authorities that detail payment of hundreds of thousands of dollars in fees by Japanese companies to a Philippine investment firm affiliated with Marcos.

Addressing members of the upper house today, Nakasone reiterated a promise for a full investigation of the revelations.

Meanwhile, a Foreign Ministry task force was convened to look into aid, especially to the Philippines. But a ministry official said it does not plan to look at the reported kickbacks, because payment of commissions is a question of "business practice."