Catholics are urging the Polish government and organizers to cancel U.S. pop star Madonna's concert scheduled for Aug. 15, the Assumption of Mary feast.

Marian Brudzynski, member of the Mazowiecki regional assembly, Wednesday said Madonna "cannot sing" on the religious feast of the Blessed Virgin Mary and announced a protest committee is being organized to stop the concert.

Brudzynski, a former member of the conservative League of Polish Families party, said Catholics will do all in their power to prevent the concert from taking place. The protest committee plans to ask Interior Minister Grzegorz Schetyna to cancel the concert, he said.

Brudzynski said if they fail to stop Madonna's concert they will stage a massive picket outside and added, "We want to stifle Madonna," Poland's thenews.pl Web site reported.

Krzysztof Zagozda, of the Catholic Society organization, said the concert would hurt Poles' religious sentiment as Madonna's performances are anti-Christian.

Stanislaw Malkowski, former Warsaw Solidarity union's chaplain, said the Catholic church and the Polish nation should protest loudly against the Madonna concert.