Cope, headed by Mosiuoa Lekota, "is interdicted, with immediate effect, from undertaking preparations for and convening a national elective congress", said Judge Fritz van Oosten.

This was pending a hearing enrolled in the court for February 1, 2013 to determine who should lead the party.

The judgment is part of the long-standing leadership battle between Lekota and expelled Cope leader Mbhazima Shilowa.

A fight over leadership between the two men at the national congress of Cope in May 2010 led to a "long line of litigation", the judge said.

In the current case, Shilowa's faction applied for an interim interdict restraining Cope "from undertaking preparations for and convening a national elective congress" pending the final determination of the action.

Van Oosten said Cope supporters had the "right to campaign and vote for the leader of their choice".

"The expulsion of Mr Shilowa is one of the issues in the action that will be determined by the trial court.

"I have not been called upon, nor is it desirable or appropriate for me, to express any views on the merits of the action.

"That being the situation I am satisfied that Mr Shilowa has succeeded in establishing a prima facie right."

The judge said it was not ideal for a court to decide on who should lead a political party.

"It is regrettable that the leadership rift and internal strife cannot be resolved within the party structure of Cope... The 'declaration' by the court of one person to be the leader of the party is anything but ideal."

Van Oosten said though it would be better to hold the elective congress as soon as possible, a delay of another four months would not prejudice Lekota or Cope.

"In the absence of Mr Shilowa an election of a party leader at the congress will in effect be nothing more than an election by default and therefore, no true election at all," the judge said.

The judgment was welcomed by the Shilowa faction.

"This judgment provides a firm foundation for the members of Cope to find a common solution to the current impasse.

"We must without delay, bring together all members of Cope under one roof and allow them to chart a solution and prepare for their organisation to play a meaningful role in the politics of this country," said MPL Zale Madonsela in a statement.