A coalition of the centre-right People's Party (ÖVP) and the far-right Freedom Party (FPÖ) has governed Austria since December after winning votes on an anti-immigration platform.
FPÖ member Gottfried Waldhäusl was quoted in an interview in Austrian newspaper Die Presse Thursday as saying registration was necessary to reduce the slaughtering used for meat consumed by Jews and Muslims.
The law provides that having such meat is only for those who show they belong to a religious community and need it, the cabinet minister in the state of Lower Austria told the paper.
Waldhäusl has said he wants to reduce the practice of slaughtering animals without first stunning them, citing animal rights.
Austria's Jewish community organisation, the IKG, said citing animal protection to crack down on kosher slaughtering was a "wrong pretext".
"To demonise the practice is a way to demonise minorities," an IKG official, who declined to be named, told AFP.
Muslim community organisation IGGÖ has also called the proposal affecting halal meat "unacceptable".
The FPÖ was founded by former Nazis in the 1950s but in recent years has sought to clean up its image, with its leader saying the party rejects all extremism.
But since its entry into government in December, the party has been embroiled in a string of controversies that critics say show it has not stamped out extremism.
In March, the FPÖ expelled two local councillors for sharing Hitler photos and quotes on WhatsApp, and in January an FPÖ candidate in a state election quit after it emerged that his student fraternity had published a songbook with lyrics joking about the Holocaust.