London's high levels of child poverty are to be tackled by a new independent commission.
Mr Livingstone will launch the commission on Monday
Across London, 41% of children live in poverty, compared with a national average of 28%.
Launching the commission Mayor Ken Livingstone said the situation was "no longer tolerable".
Its job will be to discover why London has such high child poverty rates and look at local and national policies which could reduce them.
Mr Livingstone said that while much had been done to reduce child poverty nationally, in London there had been little improvement in the past seven years.
He told BBC London high house prices and the high cost of childcare were thought to be partly to blame.
Commissioners have backgrounds in government, social care, business, academia, trade unions and voluntary sectors and will report to the mayor and the Association of London Government (ALG).
ALG chairman Sir Robin Wales said they could not allow half a million children to live in poverty while trying to showcase "what is brightest and best" about London in time for the 2012 Olympics.
Bob Neill, leader of the Conservatives on the London Assembly, said the Tories fully supported the commission.
"It is a disgrace that child poverty is so high in a city as wealthy as London," he said.
But he added that the fact a commission was needed was a "stunning admission of failure" by the government.
Last year, the issue was highlighted by Nelson Mandela and campaigners supporting the Make Poverty History rally held in Trafalgar Square.