The ANC on Saturday warned that it would discipline its members if they were responsible for blocking Cope members from preparing for a rally at the Seshego Stadium in Polokwane.

The Congress of the People accused Umkhonto We Sizwe (MK) veterans of blocking its members from preparing for a rally to be held on Sunday.

"A horde of so-called MK veterans has invaded the Seshego Stadium in Polokwane where Cope is to hold its major rally tomorrow, making it impossible for organisers to prepare the venue," said Cope spokesman, Palesa Morodu.

"They were all wearing camouflage, blocked the entrance and threatened Cope members with violence. Police were called in to monitor the situation and we will take this matter up with the IEC [Independent Electoral Commission]," she said.

ANC spokesman Brian Sokuto said the party received a complaint about the matter from Cope on Saturday and had dispatched its leadership in the area to the venue to assess the situation.

"If these are people found to be members of the ANC they should expect to be disciplined because the ANC subscribes to the IEC code of conduct . We condemn any acts of violence," he said.

Meanwhile, Cope deputy president, Mbhazima Shilowa called on President Kgalema Motlanthe to denounce what had happened.

Speaking at a Cope rally in Khayelitsha, Cape Town, on Saturday, Shilowa said Motlanthe could not say there will be "free and fair elections, yet keeps quiet when the Congress of the People is not allowed to hold meetings in the Republic of South Africa."

"He must tell us, where does he stand in the defence of the right of people to belong to the party of their choice," Shilowa said.

He said free and fair elections did not involve only what was going to happen on the 22 April. It included the entire run-up to the polls.

"That's what Mugabe did... to intimidate and threaten, to ensure that people could not hold any meetings. And then everybody said there were free and fair elections because on the day of voting everything was calm," Shilowa said.