The ticket office at Soweto's Soccer City.

World Cup organisers have admitted that more than half of the 500,000 match tickets offered for cash sale are still unsold, just over a month before the tournament starts.

Business appeared to be brisk when the fifth and final phase of sales opened in South Africa on 15 April, sparking long queues, but interest now appears to have cooled.

Greg Fredericks, who heads the office of the World Cup local organising committee CEO, Danny Jordaan, told Johannesburg city councillors that under 300,000 tickets remained for the tournament.

A Fifa spokeswoman, Delia Fischer, confirmed that 230,000 of the allotted 500,000 phase-five tickets had been sold.

Fifa moved to cash sales after widespread criticism that its online-only system was too complicated and effectively excluded millions of Africans who do not have access to computers or credit cards.

Fredericks said matches in Johannesburg, which will host the opening and final matches, and Pretoria were sold out but there were still many tickets available for matches in Polokwane, Port Elizabeth and Nelspruit.

He also said the government would soon release a transportation timetable for planes, buses and other public transport for the month-long event.