Congress of the People leader Mosiuoa Lekota, a former African National Congress heavyweight, on Monday attacked President Cyril Ramaphosa's promise to implement land expropriation without compensation, suggesting that it would not only violate the Constitution but constitute a new form of racial discrimination.

"Are you going to change the Bill of Rights in our Constitution?" Lekota asked in the debate on Ramaphosa's maiden state-of-the-nation address on Friday.

He angrily brushed off an interjection by Economic Freedom Fighters (EFF) member of Parliament (MP) Mbuyiseni Ndlozi, who asked how a former political prisoner jailed by the apartheid regime could oppose the return of land to the dispossessed.

"What were you doing on Robben Island?" Ndlozi asked.

Lekota responded by asking how Ramaphosa chose to define those whose right to property could be usurped.

"Can you tell me Mr President who is not our people? Then national party used to say others are non-Europeans. Now who is not our people?"

He listed the country's historic immigrants, from the French Huguenots to Germans who fled Nazi oppression to foreigners who flocked to be part of the Gold Rush of the late twentieth century and asked whether the president planned to expropriate the land of their descendents.

Ramaphosa on Friday told the National Assembly: "We are determined that expropriation without compensation should be implemented in a way that increases agricultural production, improves food security and ensure that the land is returned to those from whom it was taken under colonialism and apartheid.

"Government will undertake a process of consultation to determine the modalities of the implementation of this resolution."

He has mooted faster land reform as part of a drive to boost the agriculture sector.

The ruling party adopted a resolution at its December elective conference where Ramaphosa became party leader to move beyond the willing seller, willing buyer principle to seize land without compensation in certain circumstances.

The EFF earlier on Monday challenged Ramaphosa's commitment to doing so, saying it thought he was paying lip service to the policy and investors knew he was "bluffing".