By Yolanda Mufweba

It will be South Africa's biggest birthday party - but for now, no one is allowed to know how Madiba is going to celebrate his 85th next weekend.

Organisers and sponsors have gone as far as threatening legal action against service providers if they violate confidentiality. But the Saturday Star has learnt that a host of international artists will be coming to the legendary Nelson Mandela's birthday party on July 19.

The former president turns 85 on July 18, but will spend the day with his family before his big celebration the following day at the Sandton Convention Centre.

Performers such as Broadway singer and actress Barbra Streisand, R&B singer Beyonce' Knowles of the group Destiny's Child, the gloved one, Michael Jackson, and other members of the Jackson family, along with many others, will take to the stage to make the evening memorable.

Local artists include Sibongile Khumalo and PJ Powers, who a few weeks ago were both recipients of the Institute for Justice and Reconciliation Award.

Neither the Nelson Mandela Foundation, nor Coca-Cola, who will be hosting international guests during their stay, in the country were willing to divulge any information on the biggest social event of the year.

With Madiba's first birthday after 27 years of imprisonment in 1990, the media covered all aspects of the birthday celebration, from designers of celebrities' glamourous outfits to wedding preparations. Madiba married former first lady of Mozambique Graca Machel in a private ceremony on his birthday in 1998.

At least 1 600 guests will congregate at the party and it is understood that only a handful of those invited declined or were unable to attend.

The only confirmed information from the Foundation is that Madiba's cook and gardener will mingle with the stars on the night.