Freedom Front Plus leader Pieter Mulder on Sunday called on farmers to "safeguard" themselves, following ANC Youth League president Julius Malema's vow earlier in the day to "take the land without payment".
In a statement, he warned that Malema's comments on land ownership were "taking us back to the period before 1994, when violence and even the possibility of a civil war was part of the South African debate".
Mulder - who also serves in President Jacob Zuma's Cabinet as deputy agriculture minister - said there was no difference between Malema's viewpoint on land and land policy, and that of Zimbabwean President Robert Mugabe, who had destroyed his country's economy.
Earlier on Sunday, speaking at the closing ceremony of the youth league's elective conference in Midrand, Malema said there was no way to be diplomatic about land ownership.
"There is no way you can be diplomatic about the issue of land. We will never be diplomatic about willing buyer, willing seller. It has failed," he told delegates.
The leadership of the ANC had to implement the resolution taken at the party's national conference in Polokwane in 2007.
"Polokwane said willing buyer, willing seller has failed, and we must find an alternative. You have failed to find an alternative. We must take the land without payment."
Malema has in recent months become increasingly strident in his call for expropriation of land without compensation, and its speedy redistribution to the masses.
Not government policy
Mulder said the FF Plus and the majority of farmers would not accept such a solution.
"At present, these proposals are not government policy. While the debate about it continues within the ANC, it is merely being responsible if the FF Plus gives attention to contingency plans such as those which had been in place prior to 1994.
"The climate which is created by this type of comment can only lead to more farm murders and unnecessary violence. That is why the FF Plus is calling on farmers to, in their own interests, organise themselves in the interim into rural safety structures," he said.
Contacted for further comment, Mulder told Sapa he hoped the continuing debate within the ANC on the land issue would be a "logical" one.
He said farmers had been co-operating with government since 1994 on the land issue, and there remained a lot of goodwill among them towards this issue.
On Malema's comments, Mulder said: "I think it's youth speaking, but it's been so powerful I had to react."
He said the youth league president's call on land appropriation was not acceptable.
"They talk about land grab - we surely will not accept it," Mulder said.