he Vatican issued a document detailing its ban on political and union activity by priests today, and a top Jesuit leader said that his order has continuing "doubts and uncertainties" on the matter but will obey the pope's directives.

The document was prepared by the Vatican's Sacred Congregation for the Clergy to answer queries received from Roman Catholic bishops throughout the world about the ban, which was issued earlier by Pope John Paul II.

Today's document said that priests could participate in movements "to cultivate spiritual life, to promote ecclesiastical culture and to carry out works of charity and compassion in full conformity with their sacramental consecration."

But it said membership in groups that "directly or indirectly, in an open or underhanded manner, follow aims relating to politics" could not be reconciled with the legitimate apostolic role of the priest. It added that the Vatican expected compliance with its rules and that those disobeying them could be punished.

Publication of the document came 10 days after the pope emphasized many of the same points in an address to the leaders of the Jesuit order.

The Rev. Giuseppe Pittau, 53, believed to be the pope's choice as the next leader of the 26,000-member Society of Jesus, said today that the Jesuits will honor their special vow of loyalty to the pope and obey his demands.

But he said that not all "the doubts and uncertainties" had been dispelled. "Not everyone applauded the pope's action," he said, explaining that the most controversial point discussed in an eight-day meeting of Jesuit leaders that ended last Wednesday was "how to draw the line between priestly work and work that can be left to the laity."

Pittau cited "borderline cases," such as a priest who works in a Third World country where no one else is "responsible for medical aid, other things, one could almost say political things. How far can that priest go?"

Like his predecessors, John Paul I and Paul VI, Pope John Paul II has frequently criticized what he said was a confusion of roles that has led some priests to become involved in political or trade union activity, particularly in Latin America.

Last fall the pope named the Rev. Paolo Dezza, 80, as temporary head of the order, replacing the ailing Rev. Pedro Arrupe, and named Pittau as his assistant.

Pittau said today that the unprecedented involvement by the pope in the affairs of this 448-year-old order had led many Jesuits to write to the pope or to Dezza in protest but that "not one person had asked to leave the society because they couldn't accept the intervention and decisions of the pope."