Excessive bonuses have been cited as one of the causes of the downturn
A group of 72 City bankers has launched a £30m lawsuit against Commerzbank to claim unpaid bonuses.
The current and former employees of Dresdner Kleinwort claim they were only paid 10% of the bonuses they were due.
The biggest single claim is for almost £1.5m, while a number of other claims top the £1m mark.
Commerzbank took over Dresdner at the end of last year. A spokesman for the bank said it would "defend these claims vigorously".
Clive Zietman, of law firm Stewarts Law which is representing the bankers, said: "I would hope the bank would take a sensible view of English contract law and give the case very serious consideration."
The bankers believe the bonuses were guaranteed.
Commerzbank is arguing that changed circumstances brought about by the downturn invoked a clause that meant it could justifiably cut payouts.
Many have blamed excessive bonuses for encouraging the kind of short-term risk taking that helped to bring about the financial crisis.
As a result, these payouts have come under increasing pressure in the fallout from the global economic downturn.
Last month, the UK's financial watchdog, the Financial Services Authority, announced new rules to curb excessive pay.
These included deferring part of any bonus for three years to discourage short-term risk taking.
The plans were criticised by some as not going far enough.
Indeed there has also been widespread dismay that many banks could again be paying out generous bonuses.