"While James Beck became "embroiled in a public debate" with Gianluigi Colalucci, Ronald Feldman, a New York art dealer, started a petition supported by 15 well-known artists including Robert Motherwell, George Segal, Robert Rauschenberg, Christo and Andy Warhol asking Pope John Paul II to call a halt to the procedure and also the restoration of Leonardo da Vinci's "Last Supper".