One of Australia’s top writers’ festivals was cancelled on Tuesday, after 180 authors boycotted the event and its director resigned, saying she could not be party to silencing a Palestinian author and warned moves to ban protests and slogans after the Bondi Beach mass shooting threatened free speech.

Louise Adler, the Jewish daughter of Holocaust survivors, said on Tuesday she was quitting her role at the Adelaide Writers‘ Week in February, following a decision by the festival’s board to disinvite a Palestinian-Australian author.

The novelist and academic Randa Abdel-Fattah said the move to bar her was a blatant and shameless act of anti-Palestinian racism and censorship.

Prime Minister Anthony Albanese on Tuesday announced a national day of mourning would be held on January 22 to remember the 15 people killed in last month’s shooting on Bondi Beach.

Police say the Daesh militant group inspired the alleged gunmen, and the incident sparked nationwide calls to tackle antisemitism.

The Adelaide Festival board said on Tuesday its decision last week to disinvite Abdel-Fattah, because it would not be culturally sensitive for her to appear at the literary event so soon after Bondi, was made out of respect for a community experiencing the pain from a devastating event.

“Instead, this decision has created more division, and for that we express our sincere apologies,” the board said in a statement.

The event would not go ahead, and the remaining board members will step down, it added.

Former New Zealand Prime Minister Jacinda Ardern, British author Zadie Smith, Australian author Kathy Lette, Pulitzer Prize-winning American Percival Everett and former Greek finance minister Yanis Varoufakis are among the authors who said they would no longer appear at the festival in South Australia state, Australian media reported.

The festival board on Tuesday apologised to Abdel-Fattah for how the decision was represented.

“This is not about identity or dissent but rather a continuing rapid shift in the national discourse around the breadth of freedom of expression in our nation following Australia’s worst terror attack in history,” it added.

Abdel-Fattah wrote on social media that she did not accept the apology, saying “she had nothing to do with the Bondi attack, nor did any Palestinian”.

Adler earlier wrote in The Guardian that the board’s decision to disinvite Abdel-Fattah “weakens freedom of speech and is the harbinger of a less free nation, where lobbying and political pressure determine who gets to speak and who doesn’t”.

The South Australian state government has appointed a new festival board.