“So we need a strong London, but we need a Northern Powerhouse too. In the modern world growth is being powered by big cities. The top 600 cities in the world contain just 20 per cent of global population but create 60 per cent of global GDP. When you get that critical mass of people – it amplifies jobs and ideas and businesses. The cities and towns of the North of England can have that critical mass. If we join them together as a team and let them pool their strengths, if we back their scientists and innovators, if we back their thriving cultural life, make them great places to live and give them powerful elected voices, then we can create a Northern Powerhouse”.