The event on 24 March at Toynbee Hall, in Aldgate’s Commercial Street, follows War on Want’s launch for a report called Race to the Bottom.

It cited poverty wages, marathon hours and harsh treatment for employees producing clothes for the official sportswear Games sponsor Adidas, Nike and Puma.

Adidas just announced record £559 million profits, Nike has cited £1.3 billion profits and Puma recorded £71 million profits.

But, according to Race to the Bottom, workers making sportswear for the three brands earn on average only 16p an hour – in some cases just 9p an hour, well under the statutory minimum – and most toiled beyond the legal minimum of 60 hours a week.

Many employees suffered verbal and physical abuse, with sexual harassment and discrimination widespread.

Most staff lived in a single room with their families, sharing a kitchen and toilet with their neighbours.

Rahima Khatun, 21, who works as a sewing machine operator at one Adidas factory, said: "I had my first child last year, but I can’t spend enough time with her as I have to be work at the factory 12 hours a day, seven days a week. I have no choice, working overtime is compulsory. My managers are constantly swearing at us and pushing us if we don’t work fast enough. Sometimes the factory does not even pay us for three months at a time."

Speakers at the conference will include Tower Hamlets councillor Rania Khan, Amirul Haque Amin, president of the charity’s partner, the National Garment Workers’ Federation, Arifa Akter, its organiser and ex-sweatshop worker, and Sharon Sukhram, who coordinates the TUC campaign Playfair 2012.

Others will be Mzonke Poni, chairperson and founder of Abahlali baseMjondolo Western Cape, who will describe the fight against evictions over another mega sports event, the 2010 World Cup in South Africa, and former War on Want vice-chair Niaz Alam, chief operating officer at the organisation UK Sustainable Investment and Finance.

War on Want will hold the conference – entitled Blood, Sweat & Gear - together with the Battersea and Wandsworth trades union council and east London community groups.

Murray Worthy, sweatshops campaigner at War on Want, said: "Lord Coe has called the Games ‘a powerful lever of change, improving lives across the world’. Yet our research shows the appalling abuses committed by a company the Games have endorsed. If the London 2012 organisers are serious about improving lives across the world they must demand that their official partners respect basic human rights, wherever they operate. We hope they will make clear that they believe these conditions are completely unacceptable."

Blood, Sweat & Gear starts at 10.30 am and ends at 5.00 pm.

Admission to the event is free, but with limited space people should book their places at www.waronwant.org