Patti Smith, Viggo Mortensen, Massive Attack, Danny Glover and James Schamus are among scores of artists, writers and public figures who say they are “disturbed by attempts in Germany to impose political conditions on artists supporting Palestinian human rights.

In an open letter in The Guardian, they write: “We are glad that the international outcry has convinced the Ruhrtriennale arts festival to reverse its repressive decision to cancel a performance by the Scotland-based Young Fathers, after they refused to distance themselves from the global Boycott, Divestment and Sanctions (BDS) movement for Palestinian rights.”

Two weeks ago, Young Fathers had a performance cancelled by the Ruhrtriennale festival in Germany over the group’s support for Palestinian human rights. The festival announced the cancellation after a failed attempt to get the group to distance themselves from supporting the Nobel Peace Prize-nominated, Palestinian-led BDS human rights movement.

Young Fathers then reaffirmed their support for Palestinian rights and the nonviolent BDS movement, saying the festival’s decision was “wrong and deeply unfair”, and were supported by artists including Brian Eno, Miriam Margolyes and Roger Waters.

Thurston Moore, Cat Power, Tunde Adebimpe, Naomi Klein and Jarvis Cocker are among those to sign the open letter, which continues: “Ruhrtriennale’s earlier decision was a particularly alarming form of censorship, ‘blacklisting’ and repression.”

Peter Gabriel, musician and founder of Womad festival, composer Brian Eno, designer Vivienne Westwood, and actors David Morrissey, Julie Christie and Miriam Margolyes join film directors Mike Leigh, Mira Nair, Ken Loach and Aki Kaurismaki in signing the letter.

The letter, which was published in full by Artists for Palestine UK, continues: “Conflating nonviolent measures to end Israel’s illegal occupation and human rights violations with anti-Jewish racism is false and dangerous. It denies Palestinians their right to peaceful protest in pursuit of freedom, justice and equality and undermines the struggle against antisemitism.”

Record label founders Jeff Barrett of Heavenly Recordings and Don Wilkie and Ian Ilavsky of Constellation also signed the letter, along with Roger Waters, and writers Angela Davis, Judith Butler, Naomi Klein, Michael Rosen, Noam Chomsky and Archbishop Desmond Tutu.

The signatories conclude: “At a time when far right and xenophobic forces are gaining ground, we need to be more vigilant than ever in defending and advocating democratic values, including freedom of conscience and expression.”

The Palestinian Campaign for the Academic and Cultural Boycott of Israel (PACBI), a founding member of the BDS National Committee, the largest Palestinian civil society coalition, had called for the boycott of Ruhrtriennale festival: “Ruhrtriennale’s shameful McCarthyism and desperate attempt to shield from censure and accountability Israel’s far-right regime of apartheid, occupation and ethnic cleansing are glaring forms of complicity.”

Five artists had announced their withdrawal from Ruhrtriennale festival in solidarity with Young Fathers: Tony Eliah, Mazen Kerbaj, Hassan Khan, Sharif Sehnaoui and Raed Yassin. They were later re-invited.

Young Fathers were one of eight artists to cancel performances at Pop-Kultur Berlin festival last year due to the festival’s partnership with the Israeli embassy. This year, five artists including John Maus have so far withdrawn for the same reason. Brian Eno has called the partnership “a whitewash”.

The Palestinian-led BDS movement was founded in 2005 and has three aims: an end to Israel’s military occupation, equality for Palestinians with Israeli citizenship, and the right of return for Palestinian refugees in accordance with international law.