If a bank customer has an overdraft on one of their accounts, the bank can put a 'stop' on all accounts held by that customer at that bank until the overdraft is repaid. This means that regardless of the amount of the ovedraft the bank can deny you access to all the money held at that bank even if it is much more than the amount owed. Banks shold not be allowed to hold your money to ransom in this way.
All Government benefits are now paid into the recipient's bank account. This includes, Jobseekers allowance, Disability Allowances, Pensions, Child Benefit, Tax Credits etc.. All money which the Government pay people who need that money to live on. So, if a bank puts such a stop on these bank accounts they are witholding Government benefits from, often vulnerable, people. The Government should stop banks using this practise and ensure that people are not denied access to the benefits they are entitled to and need.