EU pressure on Hungary has intensified over a new law banning the depiction or promotion of homosexuality for the under-18s.
MEPs are expected to vote shortly for a resolution urging the EU to speed up legal action over Hungary's law.
EU Commission President Ursula von der Leyen said the law was "a disgrace" which contradicted "basic EU values".
Hungarian PM Viktor Orban hit back, saying school policy was a matter for Hungary, not "Brussels bureaucrats".
"Whatever they do, we will not allow [LGBT+] activists into our children's kindergartens and schools," he said.
The EU has the power to reduce budget allocations to a member state seen to have breached the EU's rule-of-law standards.