Margaret Atwood, James Norton and Ed Harris are among several stars who have signed a letter condemning “anti-LGBT rhetoric” by politicians and “homophobic aggression” in Poland.
It comes after the country’s president, Andrzej Duda, promised to protect traditional Polish values against LGBT rights in June.
The issue has come to a head in recent weeks, with gay, bisexual and transgender activists protesting against the nationalist government.
Earlier this month, thousands of people took to the streets and 48 people were arrested as protesters on both sides marched.
LGBT supporters were demonstrating against the arrest of an activist in Warsaw accused of draping rainbow flags over statues.
Now, stars are calling on the European Commission to support minorities in the country.
In a letter addressed to Commission president Ursula von der Leyen, the group say they want 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”.
There is a “persistent use of anti-LGBT+ rhetoric by Polish politicians and media”, they said.
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.
“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.”
The letter was published on Polish news website www.wyborcza.pl.