South African advocacy group AfriForum, which lobbies for the rights of white farmers, will on Thursday challenge in court President Cyril Ramaphosa's plan to change the constitution to allow land expropriation without compensation.

Ramaphosa, who replaced scandal-plagued Jacob Zuma in February, has made land redistribution a flagship policy as he seeks to unite the fractured ruling African National Congress (ANC) and win public support ahead of an election next year.

Land is a hot-button issue in South Africa, where racial inequality runs deep even 24 years after the end of apartheid. Whites - nine percent of the 56-million population - still own more than 70 percent of agricultural land.

Since white minority rule ended in 1994, the ANC has followed a "willing-seller, willing-buyer" model whereby the government buys white-owned farms for redistribution to blacks. Progress has been slow.

Afriforum, an advocacy group that mostly represents white Afrikaners, is questioning the legality of a key parliamentary committee report that recommended a change to the constitution, according to court papers seen by Reuters.

Afriforum says the committee illegally appointed an external service-provider to compile the report and also failed to consider more than 100 000 submissions opposing land expropriation without compensation.

"We want the court to refer the report back to the committee and to request the committee to repair the wrongs," Willie Spies, Afriforum's attorney, told Reuters.

Parliament, where the ANC enjoys an overwhelming majority, filed an answering affidavit arguing that Afriforum was trying to frustrate the legislative process.

Parliament says the report was produced by its staff and that it had considered all submissions.

"Afriforum’s litigation is, in any event, improper. The Report is clearly an interim step with no final effect," parliament said in court papers.

The committee's report is just one step in a long process to change the constitution. Should the court rule the report does not need to be sent back for further consideration, it is expected the National Assembly will move to adopt its recommendations early in December.

Thereafter, it is expected a new bill proposing the exact changes envisaged to the constitution will go to parliament and further public participation.

Only once both houses of parliament approve changes to the constitution will it be sent to Ramaphosa for ratification. This process is unlikely to be completed before a parliamentary election expected to be held in May.

Ramaphosa has given few details about how a constitutional change would be implemented but says any reforms will not affect investment, economic growth or food supply.