A judge in Hull is now proposing to strike out at least 44 cases by bank customers trying to reclaim their overdraft charges.
Banks are being besieged by customers asking for money back
The number of people summoned to justify their claims before Judge Ian Besford on 4 July has grown steadily since the start of the month.
He has written to them saying they have no reasonable prospect of success in the light of an earlier court case.
Despite this, many claimants are still winning their cases in other courts.
"It's going to be quite interesting, it's David and Goliath," said one claimant, Nicole Haslam.
The Birmingham judgement
Banks are facing a deluge of claims from disgruntled customers who believe they have been illegally overcharged for running up unauthorised overdrafts.
Despite arguing that the charges are quite legal and in line with the agreements that their customers signed up for, the banks have so far settled out of court in almost all cases.
However in May a judge in Birmingham, examining a claim by Kevin Berwick against Lloyds TSB, surprised observers by ruling that the bank's defence - that its charges were fees for a service and not penalties - was valid.
Although this decision did not set a precedent that other courts must follow, Judge Besford in Hull has decided that he agrees with its reasoning.
But Marc Gander, of the Consumer Action Group (CAG), said: "The Berwick case is highly specific to its own facts and the way it was presented - with no general principle laid down."
The approach of Judge Besford contrasts with that of many other judges around the country, some of whom have started complaining about the tactics being used by the banks.
They often settle at the last moment, or simply fail to turn up at all to defend the case, despite entering a written defence weeks before.
When that happens judges typically award the claim in favour of the bank's customer.
But Judge Stephen Gerlis, who speaks for district court judges in London, recently told the BBC that the emerging divergence of views among judges meant claimants might increasingly be taking part in a legal lottery.
The Consumer Action Group is helping to pay for a QC to represent some of the Hull claimants on 4 July and so far 11 have signed up to be represented by him.
"He has to argue that the judge's basis for a strike out is inappropriate in these circumstances," said Mr Gander.