Almost 3.4 million people have been claiming benefits for more than two years, Government figures have revealed.
The number of long-term benefits claimants has risen by more than 250,000 since 1999, the Department for Work and Pensions figures showed.
Tory analysis of the information showed the number of 18-24 year olds claiming for more than two years has risen by almost 40% since 1999 to over 200,000.
The worst long-term benefit blackspot is Merthyr Tydfil, South Wales, where one in five people have been claiming for more than two years.
A total of 3,352,820 people in Great Britain have been claiming handouts such as incapacity benefit, severe disablement allowance, income support and jobseeker's allowance for more than two years.
Other benefits which count toward the long-term total include bereavement benefit, carer's allowance or disability living allowance.
In total there are over 100 Local Authority areas where at least one in ten people have been claiming benefits for two years or more, according to the figures from May 2007.
The ten authorities with the highest rates of long-term claims include five in Wales, two in north east England, two in north west England and one in Scotland.
Shadow work and pensions secretary Chris Grayling said: "Some of these figures are truly shocking. In the past few years we have seen unprecedented numbers of people coming to work in the UK from overseas, yet the number of people on long-term out-of-work benefits is increasing. The situation makes no sense and needs to change."
