Exactly 20 disabled children, four from each of the five Host Boroughs, will be selected to take part in the "Mayor's Race", which is being organised by the sporting social enterprise Gold Challenge, the UK's only Olympic and Paralympic sport charity challenge.

The Gold Challenge event on April 1, which will feature Team GB ambassadors, celebrities and hundreds of representatives from schools and charities across the capital, will also see the children taking part in a special Opening Ceremony parade around the track, alongside 4,000 adults and other young people.

"This fantastic event will be held in one of the most stunning venues in the world and will give disabled children from across London the sporting experience of a lifetime," said Johnson.

"Getting people of all ages and abilities into sport is a top priority of mine and it is through the sterling work of organisations such as the Panathlon Foundation and Gold Challenge that we can make this happen.

"I am sure the day will provide a wonderful taster of what is to come later this summer when we welcome the world for the Olympic and Paralympic Games."

The 20 disabled children will be chosen by the Panathlon Foundation, the Mayor's partner charity which runs multi-sport competitions for young disabled people across every London Borough.

Panathlon is funded as part of the Mayor's £40 million ($62.5million/€46 million) 2012 Sports Legacy Programme, which is encouraging thousands of Londoners of all ages and abilities into sport.

The fund has seen substantial sums invested into projects that are focused specifically on disabled people, including the Panathlon Challenge, the British Wheelchair Basketball London Development Programme, and the Cricket for Change 'Hit the Top' programme.

"We can't thank Gold Challenge and the Mayor of London enough for giving the severely disabled children we work with the opportunity to compete on the Olympic and Paralympic track," said Panathlon Challenge chief executive Ashley Iceton.

"This really is the stuff dreams are made of.

"We are delighted our Panathletes will be among the first disabled children competing in the stadium."

The Mayor requires that every sports participation project he invests in adopts his action plan for increasing participation amongst disabled Londoners.

So far, 50 major organisations – including London Boroughs and National Governing Bodies – have adopted the "Inclusive and Active" action plan, which is creating a step change in the way that sport is delivered in London.

"We have really enjoyed working with the Mayor's Office to select the participants in the Mayor's Race and the Panathlon Foundation really is a wonderful charity," added the chairman and founder of Gold Challenge Dan Thompson.

"It is going to be a fantastic day and a unique way of saying thank you to our participants who have been inspired by London 2012 to get active and raise money for charity."

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