Government denies it risks overspending on welfare
20 June 2014 Last updated at 14:01 BST
The government has denied it risks breaching its own cap on welfare spending because of the rising costs of the main sickness benefit.
Documents seen by BBC News reveal that the Department for Work and Pensions is struggling to deliver Employment and Support Allowance, and that few other options are likely to save much money in the coming years.
Labour says ministers have overseen a "catalogue of failure" on welfare.
Michael Buchanan reports.