A new national social movement, conceived by Communist authorities as the main voice of Polish public opinion, concluded its founding congress today, sidestepping the current heated controversy over demands for a blanket amnesty for political prisoners.

A resolution entitled "Appeal to the Nation," passed by the 1,900 delegates representing the Patriotic Movement for National Rebirth, included only a single reference to the lingering repression of Poland's 1981 military crackdown. It said, "We appeal: let us do everything to make the lifting of martial law possible."

The absence of any declaration on amnesty, which the Catholic church and opposition groups have urged before the arrival of Pope John Paul II next month, underscored the new movement's difficulty in finding compromise formulas for sensitive issues and the dominance of official views in its deliberations.

Known in Polish by its acronym PRON, the organization has a mixed membership of Communist Party and nonparty people. Its stated role is to serve as a platform for political debate and as a major sponsor of social initiatives.

Signaling what could prove to be PRON's most concrete national initiative, the congress, in a document outlining the movement's activities, proposed an election reform that would include two basic changes in Poland's voting process.

It appealed for an "authentic" choice between several candidates in place of asking voters to approve or disapprove a single nominee as has been the case. It also recommended broader public participation in drafting the list of eligible candidates.

The government of Gen. Wojciech Jaruzelski is known to be considering an election reform in anticipation of next year's scheduled parliamentary elections and in view of the forced indefinite postponement last year of voting for new local councils.

PRON's three-day congress heard some strong expressions of political and social dissatisfaction, including repeated calls for an amnesty for those convicted of martial law crimes. Speeches by delegates, though largely pre-programmed, touched on a wide range of concerns, from appeals for a more liberal passport policy and more respect for farmers to a request for less censorship of reports about PRON's own internal controversies.

But the overriding tendency was to muffle evidence of conflict with the authorities and place a gloss of harmony over the fledgling movement. The final documents accepted, either by hand votes or acclamation, were watered-down versions of earlier drafts.