Contractors for four venues are now completely off-site, with Soccer City workers also reported to have walked out in a disagreement with Stallion Security Consortium.

The police were called in to provide security for last night's match between Brazil and North Korea at Ellis Park and, with a warning from the South African Transport and Allied Workers Union (SATAWU) that the strike could spread to all World Cup venues, Commissioner Cele has vowed that his force will be up to the task, even at short notice.

"We have activated necessary and adequate contingency plans to different stadia in the country," he said.

"Our priority call of action according to our mandate is to ensure the safety of the tournament as per the security guarantees. We are confident that we will not compromise the safety of the tournament or our day-to-day normal policing."

Police are now in full control of security at Ellis Park in Johannesburg plus the venues in Cape Town, Durban and Port Elizabeth. Stallion employees have also been used at Soccer City, with the remainder of stadiums' security contracted to a firm called Fidelity, who refused to give any comment on the potential for the strikes spreading to their workforce.

SATAWU's security co-ordinator Jackson Simon said the temporary workers were being "ripped off" and warned that all venues would be affected unless FIFA and the World Cup's local organising committee intervened.

Simon told Press Association Sport: "According to these workers, they were promised R500 (just under £45) a match when they signed the contract, and they are being paid R190 or R200 (less than £20). That is why they are embarking on this action.

"Most of the companies are using these workers only for this tournament, after that they will be unemployed and they are exploiting them because they know they will not be using them after these games.

"We will be effecting this strike across all stadiums unless FIFA and the local organising committee can treat this as a national interest matter."

The organising committee are set to give an update on the situation later this morning, although both they and FIFA have said they will not and cannot intervene in an employer-employee dispute.