Italian Communist Party leader Enrico Berlinguer asserted today that his party will fight for full partnership in a future Itallian coalition government.

Opening the party's 15th congress, he said Communist participation in the next government was necessary to pull the country out of the current "dangerous" situation. The statement came on the eve of a new government crisis expected to force elections in June.

The ovation given Berlinguer when he urged Communist participation in a national unity government suggested that a vast majority of delegates representing the party's 1.7 million members is supporting his policy.

Since 19738 the Communists have pursued this objective and last year they formed a parliamentary alliance with the ruling Christian Democrats. That link dissolved earlier this year when the Communists failed to get a share of Cabinet positions.

With early national elections now almost a certainty, the role of the party congress has been transformed into that of providing a political platform for the coming electoral battle.

In a two-hour speech, the Communist leader accused the Christian democrats of "ambiguity, back-sliding, closed-mindedness and arrogance" for refusing to let the Communists become bone fide Cabinet members.

Berlinguer reiterated the party's conviction that Italy's present problems cannot be solved without a goverment of national unity of which their own party would be an essential part.

"this is the basic goal of our political struggle," he said, "and the goal of our electoral battle should there be elections."

In the last elections, in June 1976, the Communists gained more than 3 million votes and came within points of overtaking the Christian Democrats. Their new-found power won them added influence, and eventually a formal role in the legislative majority.

But increasing discontent among the rank-and-file and the growing conviction of Communist leaders that the party's influence was not sufficient to curtail the power of the Christian Democrats-who have ruled here for more than 30 years-led them to a tactical political break.

The nature of Berlinguer's speech today made it clear, furthermore, that sharpening political tensions here have made party unity a prime necessity. The accent was clearly cautious and the content was centrist, with emphasis on the "historic compromise" policy of cooperation with Italy's middle-of-the road parties, qualified by recognition of the rank-and-file's desire for a tougher, position.

Observers pointed out that despite the party's evolution over the last few years, the content of the Berlinguer speech was more pro-soviet than expected.

There was great emphasis on Western European unity, criticism of the illegal aspects of socialism in the Eastern countries, and less anti-americanism than on other occasions. But Berlinguer made it clear that the Communist Party of Italy is by no means ready to deny its Leninist origins or break iits ties with the Soviet Union.