NatWest bank has been accused of injustice, abuse of power and unlawful conduct at a court hearing in London over the size of its overdraft fees.
Tom Brennan is taking his bank to court
Barrister Tom Brennan made the accusations as he applied for permission to sue the bank over its overdraft charges.
Mr Brennan is seeking exemplary and aggravated damages for harm he says was inflicted by unlawful means.
NatWest said the claim was contrived and should be dismissed.
"The claim should not be allowed to continue," argued Ben Pilling, counsel for NatWest.
The bank, he said, did not believe that its charges were unfair.
"There is no practical benefit to Tom Brennan to allow the claim to continue," he added.
He pointed out that NatWest, which is owned by Royal Bank of Scotland, had offered to pay far more to Mr Brennan than he had originally been charged.
Judge Peter Simpson, sitting at the City of London County Court, will decide if Mr Brennan - a newly qualified barrister who is representing himself - has an arguable legal case.
Mr Brennan said that the bank's scale of overdraft fees - £28 per month overdrawn and £38 per bounced item - were "egregiously invidious".
He said they were set at a level far higher than the bank needed to recover any losses through customers running unauthorised overdrafts.
"Charges are unfair because they do not reflect the actual loss to the defendant (NatWest)," he argued.
The case has been adjourned and will resume at a later date.
In an attempt to settle the case, NatWest offered to refund Mr Brennan's penalty charges, plus interest, and wipe out his remaining overdraft.
Denying any liability, the bank said it had made this offer on a commercial basis because the legal costs of a prolonged case would far outweigh the sums of money involved.
But Mr Brennan has refused to accept this.
He is pursuing his claim for damages to punish the bank for what he claims was effectively the unlawful seizure of his money, causing him economic harm.
As well as being charged overdraft fees and interest, he said that the resultant late payment charges he had to pay to credit card companies, when payments were bounced, had cost him £169.
He told the court that NatWest had made no offer to compensate him for this, even though these costs had caused him "unnecessary aggravation and stress as a result of not being able to pay rent or buy necessities."
No harm intended
Mr Pilling, for NatWest, argued that as the nub of the issue was a case of contract law, then neither exemplary damages nor aggravated damages could be applied for.
He said that less than £30 of Mr Brennan's overdraft fees related to the unauthorised overdrafts he had run up while a student.
Most had in fact been incurred by spending within his previously agreed overdraft limit.
He also denied that NatWest had intentionally inflicted harm by unlawful means, as a result of causing some credit card payments to bounce, thus reducing Mr Brennan's credit rating.
Mr Pilling said there was "no sustainable basis that the defendant intended to cause Mr Brennan harm."
Mr Pilling also argued that Mr Brennan should look to the OFT's recently launched enquiry into personal banking as a means of establishing if the banks were behaving against the interests of consumers.
But Mr Brennan rejected this, arguing that while the OFT could judge a certain level of fees to be unfair or not, it had no power to declare the charges to be unlawful.
"It is ultimately for a court to decide if a term is unlawful or not," Mr Brennan said, quoting from an OFT letter to him.
"At the end of the OFT process, individuals will still have to launch claims for repayments," Mr Brennan added.