Banks are being accused of seizing on a recent court victory in Birmingham to persuade customers to drop their claims for repayment of overdraft charges.
The Abbey's standard letter citing the Birmingham ruling
A district judge in Birmingham county court unexpectedly found in favour of Lloyds TSB earlier in May when it defended a claim for a £2,545 refund.
Now other institutions are reported to be citing the case when fending off claims from their own customers.
But many of the banks implicated by customers have denied the claims.
Consumer lobby group Which? advised people not to be put off, arguing that the Lloyds TSB case had no value as a precedent.
"This tactic may put the fear of God into people," said Which? lawyer Ingrid Gubbay. "It is treating them unfairly, and is a very aggressive attitude."
'No grounds in law'
One bank which appears to be capitalising on the Birmingham judgement is Abbey, several of whose customers have complained to the BBC News website.
Fiona Alton accuses the Abbey of trying to frighten her
Fiona Alton from Darlington has started a claim for nearly £10,000 against the bank, whose overdraft charges - she says - have crippled her and her husband's finances in the past three years.
The day after the Birmingham case, she says she received a letter from the Abbey which argued that the judgement meant there were "no grounds in law for recovering from the bank the amount of any charges he had paid to it".
Fiona was not impressed.
"They are trying to frighten the life out of everybody," she said. "They are relying on people's ignorance."
Another claimant, Graham Clarke, has received an even more brusque approach from the Abbey.
So much so that he accuses the bank of trying to bully him.
"On Friday I received a call from Abbey, the effect of which was that Abbey were quoting the judgment as a reason I should settle and offered me £90," said Graham.
"When I refused they tried to state this case means that now, I have no hope of being successful, and that the judge would look unfavourably on me continuing with the case and could award heavy costs against me for wasting Abbey's and the court's time."
The Abbey denied it was acting improperly.
"The issue regarding bank charges isn't as clear-cut as customers and the media think," said a spokesman.
"Where we are faced with the threat of litigation we feel it is entirely appropriate to ensure that customers have the full facts to hand.
"We have not, nor will we, advise the claimants on the significance of these legal developments, and we leave them to draw their own conclusions," he added.
But Marc Gander of the Consumer Action Group, a leading bank charges campaign group, said any attempt by banks to suggest the Lloyds TSB judgement was a binding precedent would be wrong.
Relying on judgement
The Clydesdale/Yorkshire group is another bank that is now taking a new tack in the light of the Birmingham judgement.
Its letter to one customer states that the Birmingham decision "confirmed that our position... is correct. The bank is confident that your claim will not succeed."
The claimant from Yorkshire, Michael Rathbone, was very annoyed.
"It is obvious that the Yorkshire bank are trying to intimidate people into dropping their claims," Mr Rathbone said.
A letter to another customer, in Portsmouth, made the new stance crystal clear.
"We will rely on this judgement in the claims you have brought against the bank," it said.
The bank also goes on to warn customers about possible costs, even though these are limited on both sides as a result of the cases being classified as small claims.
A customer in Sheffield - who wants to remain anonymous - said: "This has left me very nervous and I do not know what to do now."
A spokesman for the Yorkshire/Clydesdale denied it was trying to intimidate or scare people, and said the Birmingham case was being presented in an entirely neutral manner.
"We don't claim it is binding, and we give them copies of the judgement," he said.
"There are costs involved so our letter simply mentions this fact.
"There are some potential costs that are more than just a court submission fee," he added.
No new tactic
Other banks have been accused of adopting this more vigorous approach in trying to persuade claimants to settle.
Barry Mills was not impressed by his bank's letter
Barry Mills, from High Wycombe, received a letter from HSBC citing the Birmingham case one day after the judgement.
"I think it's just another tactic to get out of paying all the money," said Barry.
HSBC said it had definitely not adopted a new policy of citing the Birmingham judgement in standard letters to claimants.
A spokesman explained that it had been mentioned in an exchange of letters about legal cases, which had been initiated by Mr Mills, and it was certainly not claiming that the Birmingham ruling was binding.
But a bank spokesman added: "It is not unreasonable to point out there has been a judgement."
Another BBC reader, Robert, from Altrincham, reports receiving a phone call from the Royal Bank of Scotland last week, offering him a partial refund of £1,150 on his claim of £3,300.
He was not impressed when the bank's employee told him the Birmingham case meant its charges were valid.
"She was really snotty," he said. "She was trumpeting the fact that someone had lost in court."
However, RBS said it was not the bank's policy to quote the Lloyds TSB court victory to customers.
"We have... found absolutely no evidence of staff referring to this judgement," a spokesman said.