Contrary to press reports, no permission for Gravel's political involvement was provided by the Vatican, the bishop said.

"No 'green light' has been given by the Vatican," he said. "The position of the church is clear: all priests must abstain from all militant engagement in politics."

Though there can be "truly exceptional, concrete circumstances" for making an exception, Lussier said no such circumstances exist in Canada.

Lussier also said church law gives the authority for making this decision in this case to the local bishop, who must consult with his priests' council before doing so.

Gravel, a parish priest of St. Joachim Church in Sainte Anne des Plaines in Quebec, was the unanimous choice for the separatist party, which is running him in a Nov. 27 byelection to replace member of Parliament Benoit Sauvageau, who died in a road accident.

When Gravel was sworn in as the Bloc Quebecois candidate Oct. 29, he was no longer eligible to administer the sacraments. He told local media that he will miss saying Mass and celebrating the sacraments.

"By making the choice to take part in party politics, Fr. Gravel retains the clerical state, but he is relieved of the exercise of sacramental duties," Lussier said. "He cannot exercise any activity as a priest during his time of involvement in politics. This measure aims to avoid any confusion among the faithful and preserve the distinction between the political function and religion."

Lussier added that, in any such case, "the fact of renouncing the exercise of sacramental ministry always represents a painful situation for the church."

Gravel is a charismatic figure in the community, and his chances of being elected are high in the traditionally safe Bloc riding. But in recent years, he has been in newspaper headlines for defending gay marriage and abortion.

He told local media that, if he is elected, he will abstain from voting on gay marriage rights when Parliament revisits the issue.

(with files from Catholic News Service)