A Philippine Cabinet minister who is election campaign manager for President Ferdinand Marcos today accused elements in the U.S. government of seeking to "destabilize" the Marcos administration and cause its defeat in an election next month.

Labor Minister Blas Ople said Washington's "mindless policy toward a close ally" represented "real meddling" in Philippine affairs and "imperialist retribution" against Marcos.

"I can see a whole arsenal of destabilizing weapons being trained against the Philippine government," Ople said in a weekly breakfast forum. "President Marcos is being destabilized because he refuses to bow down to this new American imperialism."

In an interview afterward, Ople said, "If the Americans do not watch out, this kind of naked meddling . . . can lose them the Philippines."

In an appearance before the Rotary Club, U.S. Ambassador Stephen Bosworth today rejected charges of meddling. He indicated in a speech that the United States would increase aid to the Philippines if a "credible" government emerged from the election that pursues major political, economic and military changes long promoted by the United States.

Ople's comments came in response to a series of disclosures in the United States about wealth invested there by the Marcos family and U.S. press reports on Marcos' World War II record. Ople said reports challenging Marcos' war record were "very painful" for the 68-year-old president. He suggested there might be "an unseen hand orchestrating these attacks on President Marcos" in collusion with the Philippine opposition as the Feb. 7 election date approaches.

"It's too perfect a coincidence," Ople said. "It's a kind of transpacific conspiracy."

Stung by the reports challenging his longstanding assertions about heroic exploits in World War II, Marcos has been mounting a campaign in recent days to restore his credibility on an issue that has underpinned his entire political career.

Filipino veterans have come forth to publicly corroborate Marcos' claims, and members of the guerrilla group Marcos allegedly led into battle against the Japanese have filed libel suits against two Manila newspapers that reprinted articles from The New York Times and The Washington Post about Marcos' war record.

Progovernment Manila newspapers have expressed outrage over the disclosures, with one columnist charging that "American journalistic AIDS" was "running rampant and wild in this country."

So far, the opposition has not tried to make much of an issue of Marcos' war record.

Opposition presidential candidate Corazon Aquino said in a statement yesterday that Marcos' exposure as "a fake war hero does not come as a surprise. It only underscores the deceitful character of the man who ruined what was once Asia's showcase of democracy."

One of Aquino's campaign managers, former senator Ernesto Maceda, said the war record question would "be mentioned only in passing" in campaign speeches, with most of the attention focused on the issue of wealth invested abroad by Marcos; his wife, Imelda; and various presidential friends and relatives. Maceda said the war record "is not as important an issue as economic bread-and-butter issues."

One reason for wariness about the war record issue, political observers said, is that the father of Aquino's running mate, Salvador Laurel, was president during the Japanese occupation, and her father-in-law was a wartime Cabinet minister.

After an angry initial reaction, Marcos quickly took a different tack by describing the stories about his war record as "almost laughable" and as "an accolade" to him.

This prompted an opposition newspaper columnist Ninez Cacho-Olivares to ask today, "But why file lawsuits for something 'complimentary?' "

Amid reports from Washington that the Reagan administration is distancing itself from Marcos, Ople accused a "certain ideological wing of the U.S. establishment" of seeking to oust Marcos in "a very reckless emotional approach to the Philippines problem." In the interview, he said President Reagan and Vice President Bush retained "correct political instincts" but were being "overwhelmed" by others, including congressmen such as Rep. Stephen Solarz (D-N.Y.) and Sen. Richard Lugar (R-Ind.).