The European Parliament has called on Poland to stop public leaders inciting discrimination against homosexuals.
The resolution follows a statement by a deputy education minister that Poland was drafting a law to punish teachers who "promoted" homosexuality.
Poland's PM later said there would be no discrimination against gay teachers.
But MEPs repeated an appeal to EU anti-racism experts to look into "the emerging climate of racist, xenophobic and homophobic intolerance in Poland".
They asked the Polish authorities to "publicly condemn and take measures against declarations by public leaders inciting discrimination and hatred based on sexual orientation" and called on European Parliament leaders to send a fact-finding mission.
In a debate on the resolution on Wednesday, British gay MEP Michael Cashman said a country that had lived under repression should know the value of fundamental human rights.
"You should be teaching us about fundamental values and that is why we will not hesitate to defend human rights and human rights' defenders wherever they are," he said.
But Polish MEP Witold Tomczak said homosexuality was against the law of nature, and called on "so-called defenders of human rights" to tackle "discrimination against normal families".
"Every person has a right to life and deserves respect and help, including one who - lost and scarred - has given into homosexual tendencies.
"The solution is to help those who suffer and to provide them with the cure that they expect us to deliver."
Several Polish MEPs walked out of the chamber when attempts to prevent the debate failed.
Poland's deputy education minister, Miroslaw Orzechowski, said last month that a law banning the promotion of homosexuality in schools would be finished within weeks.
Human rights organisations said it would prevent lessons promoting tolerance towards homosexuals, and the dissemination of lifesaving information about Aids.
"It was not just any person who made this dreadful statement, it was a member of the government, helping to contribute to a climate in which hatred is regarded as normal," said Dutch MEP Sophia in't Veld.
Employment and Equal Opportunities commissioner Vladimir Spidla warned that any measures banning discussion of homosexuality in schools would violate European law.
Mr Orzechowski is a member of the League of Polish Families, a junior partner in the coalition led by Mr Kaczynski's Law and Justice Party.
The AFP news agency reports that an MEP from the League of Polish Families, Maciej Giertych, has published a pamphlet stating that homosexuality is "biologically useless" and "reversible" as long as there is "the desire to become heterosexual and the spiritual motivation".