Poland’s chief rabbi has said Polish-Jewish relations are at their worst for 30 years as controversy rages over a new law that critics claim is an attempt to whitewash Polish crimes against Jews during the Second World War.

Michael Schudrich’s comments came just hours after vandals scrawled swastikas and anti-Polish statements on the Polish embassy in Tel Aviv, demonstrating the level of anger over the law, which has made it a criminal offence to blame the Polish nation or state for crimes by the Third Reich.

Over the weekend Mateusz Morawiecki, the Polish prime minister, provoked even more anger in Israel and among Jews worldwide when, speaking in defence of the law, he said Jews were also perpetrators of the Holocaust.

“Sadly [Polish-Jewish] relations are the worst I can remember,” Rabbi Schudrich said in a radio interview on Monday. “This is the worst moment in 30 years.

“I am, and I hope I always will be, an optimist,” he continued. “But now I am an optimist with a broken heart.”

Earlier, Benyamin Netanyahu, the Israeli prime minister, had tweeted that he considered the Polish prime minister’s comments “outrageous” and that he wanted to address the issue with Mr Morawiecki.

On Monday Jacek Czaputowicz, Poland’s foreign minister, said he had called upon the Israeli authorities to ensure the safety of the Polish embassy and to catch the perpetrators of the swastika attack.