World Cup organisers have admitted that the deadline for completing two of the five stadia being built for the 2010 finals in South Africa is "very, very tight".

Plans to hold the Confederations Cup at the Nelson Mandela Bay Stadium in Port Elizabeth a year before the World Cup may have to be shelved due to construction delays.

Organisers insist there is no threat to the World Cup taking place but concede there are also concerns about building work on the Green Point stadium in Cape Town.

Tim Modise, communications director of the 2010 organising committee, said: "The guarantees we gave FIFA are being satisfied and we are very proud that one stadium, Soccer City in Soweto, will be delivered five months ahead of schedule.

"Things are on course generally but with two stadiums the timelines are very, very tight.

"The Nelson Mandela Bay Stadium has been earmarked for the Confederations Cup in 2009 so that makes it even tighter and in the next two months we will decide whether it can be used for that tournament or not."

Tourism chiefs expect 450,000 fans to travel to South Africa for the finals, and spend €1.1billion.

However, crime remains one of the big disincentives for travellers and Moeketsi Mosola, chief executive of South African Tourism, accepted that some fans might be put off.

He said: "We are working with all the authorities to ensure safety - and if we are sure our people are safe then the visitors will be safer.

"The number of police in uniform will rise from 140,000 to 190,000 in the next three years to have a more visible presence."

Modise, speaking on a visit to London, said South African authorities would also liaise with foreign police forces and football associations to draw up plans to deal with potential hooligan threats and for anti-terrorism measures.