The Tories’ Northern Powerhouse plans were today described as “hollow talk” after a newly published report revealed the scale of the North/South divide.

Of the 12 towns and cities facing the greatest economic decline in the UK, 10 are in the North of England, with one in Scotland and one in the Midlands. None of the top 24 cities in the index, released by the Joseph Rowntree Foundation (JRF) today, are from southern England.

The results show that the Conservative Party is “letting down the North”, said Shadow Business Secretary Angela Eagle, in what will come as a further blow to Chancellor George Osborne, who has been the face of the flagship Northern Powerhouse programme.

The research studied 74 towns and cities with populations of over 100,000, and based the index on changes in employment rates, levels of highly-qualified workers, the number and type of full-time jobs, net migration rates and population change.

Some of the areas could benefit from newly devolved powers, with Rochdale, Wigan and Bolton all falling within Greater Manchester, which will elect a metro mayor for the first time next year. However, towns such as Burnley and Blackburn are less likely to see the benefits of devolution to city regions, despite some work to improve transport links.

The JRF says that current devolution plans are focussed on the UK’s larger cities, and that “for wider prosperity and rebalancing, areas outside the biggest cities must also share in the benefits of investment and devolution.”

Angela Eagle said that many places ran the risk of getting left behind in the Government’s devolution plans.

“As so often with this Tory Government the headlines are very different from the reality, and this report shows that some places risk being left behind,” she said.

“For all their hollow talk of supporting the North and devolving power, the truth is progress on infrastructure has stalled and major projects have been delayed.

“The Tories are letting down the North, just as they are letting down working people right across Britain.”

The twelve places facing the biggest economic decline are: