Madonna has been accused of "Satanic provocation" for performing in Poland on a religious day.
The Material Girl was criticised for holding the gig, part of her Sticky & Sweet tour, in Warsaw on August 15.
This is the date of the Feast Of The Assumption when Mary ascended to Heaven according to Catholic doctrine.
At a press conference held last month, ex-president and Solidarity founder Lech Walesa said: "It is a Satanic provocation. I am a man of faith and ask for such events not to happen on such an important feast in my religion."
Protest leader Father Stanislaw Malkowski added: "This is an attack by the devil on our immaculate Catholic nation. This concert is a profanity and blasphemous."
Parliamentarian Marian Brudzynski, who has promised two weeks of protest over the date, said: "The concert of a highly perverse singer who calls herself 'Madonna' is deeply humiliating to Warsaw residents and Poles in general."