The debate is all about "default" bank charges, i.e. those charges that banks levy if you go overdrawn (or exceed your overdraft limit) without permission, or have a cheque, direct debit or standing order unpaid due to insufficient funds. These charges have been part of the banks' published tariffs for many years, and were originally intended as a way of ensuring that costs of administering "delinquent" accounts was borne by the customers whose accounts caused the costs, and not by those who did not. Not unreasonable in itself, but over the years, that idea became lost as the fees got higher and higher, to the point where they became a primary source of income rather than merely a way of apportioning and recovering costs.
Now, the Office of Fair Trading is following up an investigation it conducted last year into similar charges on credit cards by tuirning its attentions to current accounts. The OFT's view (albeit hotly contested by the banks) is that under Unfair Terms in Consumer Contracts legislation, a charge may not be lawful if it exceeds the actual cost of the administrative work it represents. Banks are steadfastly refusing to reveal what their costs are, but some estimates have suggested that about £6-8 is a reasonable level for the charge. Most banks charge between £30 and £40 per time.
So, if you have incurred this type of charge in the last 6 years, you can ask for them back from your bank by claiming they are unlawful. The Bank must then choose whether to refund them or defend them, either by arguing that the OFT's interpretation of the legislation is wrong, or by arguing it is right but releasing information about its costs to prove that the level of the charge is fair (which as I said, they won't do).
Most banks tend to reject the complaint at first go, then make an offer of a partial refund if you persist. If you still insist on a full refund (which you should) the bank will typically refuse and refer you to the Financial Ombudsman Service.
They are hoping you will be put off and eventually give up. Don't!
Take it all the way to the ombudsman, and there is a good chance you will get all your charges back.
This website is a good starting place, particularly for the template complaint letter. Good luck.
http://www.which.co.uk/reports_and_campaigns/money/campaigns/Banking%20and%20credit/The%20ASBO%20campaign/what_you_can_do_559_74997.jsp