Up to 20 jobseekers are chasing every vacancy in parts of the country, according to a study published on Tuesday.
Research by the think-tank IPPR North showed that the worst-hit area was West Dunbartonshire (20 jobseekers per vacancy), followed by Clackmannanshire (19), East Ayrshire, Hartlepool, Blaenau Gwent, Lewisham, North Ayrshire, the Isle of Wight and Gravesham (all 16).
Northern urban areas were particularly badly affected, as well as the West of Scotland, South Wales and some seaside towns, the report revealed.
In contrast, some areas had only one or even no jobseekers for vacancies, including Crawley, Cambridge, South Buckinghamshire, North Warwickshire, Daventry and the City of London.
Ed Cox, director of IPPR North, said more needs to be done to help the areas of the UK where people are really struggling to find work.
"The government should guarantee a job for everyone who has been unemployed for more than a year paid at the minimum wage, targeted at the worst affected areas first but then rolled out everywhere," he said.
The report was published ahead of new unemployment figures on Wednesday, which analysts expect will show another rise from last month's figure of 2.6 million.
It also comes as the TUC warned "mass redundancies" in the NHS, local authorities and other parts of the public sector will have a "devastating" impact on local economies.