The City Growth Commission, headed by Mancunian economist Jim O'Neill, will make its case for greater financial devolution in the autumn, aimed at influencing all political parties before the next General Election.
Speaking at an event on the Manchester stand in the Palais des Festivals, Cannes, O'Neill said "London's growth is fantastic for the UK" but regional cities need greater autonomy to share the capital's momentum and help enhance overall national productivity.
O'Neill emphasised the importance of linkages between global trading cities, especially connecting those in the developed world and in emerging markets such as China.
The presentation, introduced by Sir Howard Bernstein, chief executive of Manchester City Council, was the first on the Manchester stand, themed blue this year and dubbed the Blue Moon by Bernstein in his welcome comments to the packed room of delegates.
The City Growth Commission is running for 12 months to gather evidence for greater financial and policy devolution from government before it publishes its findings in October.
The commission is chaired by O'Neill, former chair of Goldman Sachs Asset Management, and now a professor at Manchester University, specialising in urban economics.
O'Neill and his panellists are building the case for the "growth of urban Britain outside of London, but not at London's expense" he said. Large regional cities need to understand which bits of London's "wonderfulness" they can capture to help give the UK economy a boost, said O'Neill.