In June, the country’s president Andrzej Duda promised to protect traditional Polish values against LGBT rights.
The letter, which was addressed to European Commission president Ursula von der Leyen, said the group wish to voice their “grave concern about the future of democracy in Poland, a country with an admirable history of resistance to totalitarianism and struggle for freedom”.
It added that there is a “persistent use of anti-LGBT+ rhetoric by Polish politicians and media”.
“Homophobic aggression in Poland is growing because it is condoned by the ruling party, which has chosen sexual minorities as a scapegoat with no regard for the safety and well-being of citizens,” the letter said.
“We call on the European Commission to take immediate steps to defend core European values – equality, non-discrimination, respect for minorities – which are being blatantly violated in Poland.
“LGBT+ rights are human rights and must be defended as such.”
In addition to The Handmaid’s Tale author Atwood and actors Norton and Harris, the letter was also signed by writers Anne Enright and Ian McEwan, director Mike Leigh and actress Isabelle Huppert.
The letter was published on Polish news website www.wyborcza.pl.