The Chief Rabbinate of Israel has threatened to break off normal dialogue with the Vatican over its decision to lift the excommunication of a Catholic priest who claimed that no Jews died in gas chambers during the second world war.
In a letter to Cardinal Walter Kasper, president of the Holy See's Commission for Religious Relations with Jewry, officials from Israel's supreme religious governing body warned that without a public apology from the priest it would be "very difficult to continue dialogue with the Vatican as before". The letter called on the priest, British-born Richard Williamson, to recant his "deplorable" statement.
The letter said: "You will appreciate that under such circumstances it would be wiser for us to postpone our next meeting in Rome at the beginning of March until this matter is clarified."
It is the fiercest criticism yet of the papal decree, issued last weekend, aimed at rehabilitating members of a traditionalist Catholic order - the Society of St Pius X - one of whose clerics is a Holocaust denier.
Williamson, who now lives in Argentina, had claimed in a television interview that historical evidence was "hugely against six million having been deliberately gassed in gas chambers as a deliberate policy of Adolf Hitler ... I believe there were no gas chambers."
Alongside three bishops, Williamson was excommunicated 20 years ago after being consecrated by French archbishop Marcel Lefebvre without papal consent.
The letter, signed by Oded Weiner, the director of the Chief Rabbinate, said: "Even if the move in itself was not intended in any way to relate to the church's relationship with the Jewish people, when it involves the embrace of someone who publicly expresses such odious and outrageous opinions, then it definitely does affect our relationship."
Yesterday Weiner told the Guardian the Rabbinate was demanding an explanation from the Vatican. "This relationship is very important for us and the Holy See. We have not cut ties with them. We are saying the matter has to be clarified. They are aware of the pain and sensitivity and they will consider it and send it up to the highest authorities."
His comments came as the pope made his first public remarks on interfaith relations. Referring to his recent commemoration of the Holocaust, he highlighted how at Auschwitz "millions of Jews were cruelly massacred, innocent victims of blind racial and religious hatred". At his weekly audience, yesterday Benedict XVI told thousands: "I once again affectionately express my full and indisputable solidarity with our brothers and sisters who received the first covenant. I trust that the memory of the Shoah will induce humankind to reflect upon the unpredictable power of evil when it conquers the heart of man."
The row, however, shows no immediate sign of abating. The Nobel peace prize winner and death camp survivor, Elie Wiesel, said that the pope, by lifting the excommunications, had given credence to "the most vulgar aspect of antisemitism".
In an interview with Reuters, Wiesel said: "What does the pope think we feel when he did that?"