Sepp Blatter, Fifa president, has admitted he has a "Plan B" organised should South Africa be unable to host the 2010 World Cup, but it will only be used if a disaster makes holding the tournament impossible there.

Blatter, speaking at a press conference before Sunday's Euro 2008 final between Germany and Spain at Vienna's Ernst Happel Stadium, said the tournament would only be taken away from South Africa in dire circumstances.

"I would be quite negligent as president if I did not have a Plan B tucked away at the back of a drawer," Blatter said.

"But only a natural disaster would make it active," he added, putting aside doubts over security and possible delays over construction of stadiums.

Safety is a major concern for the tournament in South Africa where there are dozens of murders every day, with a recent wave of violence against foreigners doing nothing to ease fears.

Fifa will give 150,000 free World Cup tickets to South African football fans, with unemployment running at 40 per cent and the average wage $1100 per month.

Six officials

Next year's Confederations Cup, from June 14 to 28, will be a big test for South Africa in the traditional warm-up before the World Cup is held there a year later.

"If we had to activate the Plan B, we would do it after the Confederations Cup," said Blatter.

The Fifa chief added the Confederations Cup will be used by the world's governing body to test the idea of using six officials at each the game, including a referee assigned to each penalty area to help control the game.

"It would be interesting on a psychological level, because the players would know they are being observed in the penalty area," said Blatter.

"We will test this idea next year."

However Blatter passed off any suggestions of a video referee to give his verdict on key situations in a game, or the idea of having a micro-chip to confirm whether a goal had been scored, saying the ideas had been "suspended".