According to the Hungarian PM's chief of staff Gergely Gulyas, the Hungarian party would immediately leave the conservative bloc, known as European People's Party (EPP) if the EU decides to suspend it.
"It is about the dignity of Fidesz and the country", he told state news agency MTI.
Addressing the situation, German conservative leader Annegret Kramp-Karrenbauer said earlier in the day that a membership "freeze" for the Hungarian party would be an option.
"As long as Fidesz does not fully restore trust there cannot be normal full membership", Kramp-Karrenbauer told Reuters.
The statement comes after European Commission head Jean-Claude Juncker told German radio he had advised the centre-right European People's Party to kick out Fidesz, accusing the Hungarian politicians of spreading "lies".
The decision followed a "Stop Soros" bill, adopted by the Hungarian Parliament in 2018, which criminalised giving unauthorised assistance to illegal immigrants, also allowing to impose a ban on the activities of pro-immigration human rights groups.