Parliament - Deputy Mineral Resources Minister Godfrey Oliphant called Economic Freedom Fighters leader Julius Malema a "Judas".
Speaking during the State of the Nation Address debate on Tuesday, he said the EFF were cowards and Malema was a traitor for speaking negatively about former president Nelson Mandela during a trip to London in November last year.
"He is in fact a Judas," said Oliphant.
The EFF's MPs left the National Assembly after Malema's speech.
The firebrand leader told the House he would not take part in a debate on a SONA delivered by an "illegitimate" president.
Malema apologised for maligning Mandela and former president Thabo Mbeki, saying Zuma had misled him.
Malema had accused Mandela of being a sell-out during negotiations to establish a democratic South Africa.
He made too many concessions and did not rectify structural wrongs and the unequal distribution of resources, Malema said at the time.