The proposal was announced by heritage council leader Themba Gwabeni, who said Terre'Blanche and his party were part of South Africa's history.
Everybody had the right to celebrate their heritage, including the Afrikaner Weerstandsbeweging (AWB).
The SA Communist Party in the province said this was insulting and Terre'Blanche was not a hero.
Terre'Blanche, who opposed racial integration, was convicted of attempted murder and assault of a worker. One of his farmworkers murdered him in 2010.
SACP North West secretary Madoda Sambatha said people still lived with the scars of his actions, and many white people, including Afrikaners, were ashamed of him.
"We call on our own government and our ANC not to even start any debate around that proposal," said Congress of SA Trade Unions North West secretary Solly Phetoe.
Gwabeni was an African National Congress municipal mayor for the Ngaka Modiri Molema district and defected to Cope after taking the ANC to court when it put the municipality under administration.
The AWB refused to comment, but conceded it intended to have its former leader's house declared a heritage monument.