Cities in the South East of England are nearly twice as productive as other places in Britain, according to new research.
The Centre for Cities think tank has called on the Government to improve national productivity by tackling skills gaps and improving infrastructure throughout the country.
It says many firms locate high-skilled operations in London and the South East where they have access to a skilled workforce and other relevant businesses, while placing lower-skilled operations in other parts of the country where land and labour is cheaper.
The think tank says the national economy would be £203bn bigger if all British cities were as productive as those in the Greater South East.
The most productive UK city according to the research is Slough, with an average output per worker of £82,100, twice as high as the least productive cities, followed by London with average output of £73,700.
Centre for Cities, chief executive, Andrew Carter said: 'The Government should focus its efforts to improve national productivity on addressing the issues that hold cities back, such as tackling skills gaps or improving infrastructure.
'Doing so will have a greater impact than measures aimed at boosting specific sectors, and should be a top priority in both the Budget and upcoming industrial strategy.'