Ten of the UK's 12 most struggling towns and cities are in the North of England, new research shows.
Critics say the findings undermine George Osborne's plan to create a Northern Powerhouse to bridge the North-South divide.
Rochdale's economy is declining most steeply, followed by Burnley, Bolton, Blackburn and Hull, according to a report by the Joseph Rowntree Foundation.
None of the top 12 struggling areas are in the South, and growth in most was found to be lagging significantly behind national levels.
The table was compiled following a study of employment and migration rates in the areas, numbers of highly qualified workers and types of jobs. For the purposes of the research, urban areas with a population of at least 100,000 were described as "cities".
:: What Is A Northern Powerhouse?
The Chancellor's plan to create a Northern Powerhouse is about rebalancing the UK economy and pushing growth outside London in the northern cities.
Josh Stott, policy and research manager at JRF, said the Treasury needed to ensure "areas outside of core cities are not left behind".
"Britain has the potential to become a more prosperous country, with George Osborne's Northern Powerhouse playing a key role in rebalancing the economy," he said.
"But it must reach all parts of the North to ensure prosperity is shared."
A Department for Communities and Local Government spokesman said: "The Northern Powerhouse will transform our great northern cities and rebalance the economy, having already helped create record employment rates and getting more than 440,000 people into work since 2010.
"So far we have secured a host of devolution deals, and invested in transport, science and the arts across the region, backed by more than £4bn of new funding from central Government.
"We want to harness the North's massive potential to drive the UK's economy, and its prospects make it a lucrative place to invest and live."