An upsurge of Communist rebel activity recently has generated a controversy over the prospect of calling for help from U.S. troops and a public debate between two key government ministers on the seriousness of the guerrilla threat.

At issue are conflicting statements by Philippine government officials, including President Ferdinand Marcos, that appear symptomatic of the administration's confusion over the Communist rebellion and what to do about it. The controversies also reflect the government's sensitivity about the growth of the insurgency, which diplomats say can be seen as an indictment of Marcos' 20-year rule.

The latest assessment of the insurgency came today from the acting armed forces chief of staff, Lt. Gen. Fidel Ramos, who told a news conference that the Philippine military "can handle the insurgency in its present proportions for as long as there is no significant or sizable or recognizable foreign support or intervention . . . "

Asked about a recent remark by Marcos on the prospect of calling for U.S. troops under the Mutual Defense Treaty signed in 1951 with the United States, Ramos said that if the insurgents received significant foreign intervention or support, "then we might be compelled to invoke the Mutual Defense Treaty."

The question at this point is largely academic. It is generally agreed that the estimated 12,000 guerrillas of the New People's Army, the armed wing of the Communist Party of the Philippines, are waging a home-grown rebellion with little or no foreign financing or material support.

Nor is the government, or any other group in the Philippines, seeking intervention by U.S. troops in the conflict. Even if they were, according to U.S. officials, it is doubtful that an essentially domestic insurgency would fit Washington's definition of an "external armed attack" -- the language in the treaty -- that would trigger U.S. intervention.

The controversy arose when Marcos told the Paris-based Gamma television last week that "our policy is we will not allow the entry of foreign ground troops into our country to fight our internal wars while we can do it, but if the infiltration and subversion is so massive it gets out of control, then we might."

The following day he gave a slightly different answer in an interview with The Washington Post when asked if he could envisage any circumstances in which U.S. involvement in counterinsurgency operations might be sought.

"No, I cannot," Marcos said, "because it is our policy to fight our internal wars alone." He added, "We will not allow any foreign troops to come in, unless it's an outright infiltration of massive enemy troops." Marcos stressed that with "indigenous forces" of the Philippine military, "ultimately, we'll wipe out the insurgents."

But recurring questions about the Gamma interview, excerpts of which were published here, prompted Marcos to issue a "clarification" that appears to have further muddled the situation.

The clarification said: "If the integration of aid and foreign-trained troops is so massive that it is equivalent to outright attack or aggression against us, then we may have to ask the help of allied troops, as provided for under the mutual defense pact."

Political opposition leaders jumped on even the remote suggestion of seeking foreign troops to denounce Marcos anew and demand his resignation on the grounds that he "no longer reflects the will of the people" and can no longer "control the situation."

The controversy has refused to die despite disclaimers such as one issued yesterday by Michael Armacost, the U.S. undersecretary of state for political affairs. He said at the end of a weekend visit here that the subject of calling for U.S. troops never came up during a meeting with Marcos.

"I personally doubt that foreign troops are an answer to this kind of problem, particularly in the absence of any indication that there is very active foreign support being provided to what is an internal insurgency," Armacost said.

Compounding the confusion has been a debate in Manila's press between Labor Minister Blas Ople and Defense Minister Juan Ponce Enrile over Ople's warning last week that time is running out to avoid a "slide to civil war" and a "march to mass fratricide."

Enrile responded by chastising Ople for portraying the Communist insurgents as stronger than they really are.

Ople said he never suggested civil war was "imminent," but warned that it could result unless an alert nation acted to reverse the threat.