A planned trip by Pope Benedict XVI to Israel could be “complicated” by the situation in Gaza, but not by a controversy over his decision to reverse the excommunication of an apparent Holocaust denier, a high-ranking prelate said Monday.

“The organisation of the visit is tied mainly to political questions,” Cardinal Walter Kasper said in an interview with the Italian daily La Repubblica, adding that it would be “complicated [by] the events in Gaza”. He also said that statements by British Bishop Richard Williamson on the Holocaust were “unacceptable” and “stupid” and “have nothing to do with the Catholic Church,” but added the Pope’s May 8-15 visit, which has yet to be confirmed by the Holy See, “does not depend” on the controversy.

Williamson has dismissed as “lies” that gas chambers were used by the Nazis to kill millions of Jews before and during World War II.

Kasper, who handles the Vatican’s relations with Judaism, said the Pontiff’s trip to Israel will be “complicated” by the 22-day Israeli offensive in Gaza that ended January 18.

“In any case, no decision has been taken yet, and the programme has not been set. It depends on how the situation develops on the ground,” he said, stressing that “the situation must be calm” for the visit, and that the Pope will want to “meet his people” in Bethlehem.

On Williamson, Kasper added: “I understand that statements by Williamson can cast a shadow over relations with Judaism, but I am sure the dialogue will continue.” The Pope last week cancelled the 1988 excommunication of Williamson and three other bishops in a bid to heal a 20-year schism with Catholic traditionalists led by rebel French archbiship Marcel Lefebvre.

In an interview aired by Swedish SVT television on Thursday - two days before the announcement of the Pope’s decision - Williamson said: “I believe there were no gas chambers.... I think that 200,000 to 300,000 Jews perished in Nazi concentration camps but none of them by gas chambers”. He added: “There was not one Jew killed by the gas chambers. It was all lies, lies, lies!” Several Jewish leaders and organisations, including Israel’s Yad Vashem Holocaust memorial and the Simon Wiesenthal Centre, denounced the Pope’s decision.