A Liberal Democrat MP has claimed that banks are 'robbing' their customers.
Matthew Taylor, shadow minister for social exclusion, argues that the £4.5 billion banks charge customers annually in penalty charges is "the biggest bank robbery in Britain – against their own customers".
He urged banks to act to improve their conduct before the findings of the Office of Fair Trading (OFT) are made public.
The watchdog is currently subjecting penalty charges to the same scrutiny it shone on credit card fees last year, when credit card fees were found to be illegal and unjust, with too wide a gap between the administrative costs incurred by banks processing customers' late payments and the fees imposed.
"If the banks postpone reducing their charges until the OFT findings are published, they are clearly ripping off their customers to make billions of pounds in unfair profits," Mr Taylor claimed in the House of Commons debate.
He went on to urge customers to "phone their bank to claim [penalty charges] back".
But economics minister Ed Balls stressed in his response that it was not for ministers to "set the pace" of the OFT inquiry, which he believed banks were already taking "very seriously".
Find out more about reclaiming bank charges