Europeans face a looming crisis that could see their personal finances wiped out should the EU and UK not come to an agreement on cross-border contracts post-Brexit.
That is according to a new report from TheCityUK, which reveals that 36 million insurance policyholders, and £26trn in outstanding uncleared derivatives contracts are at risk.
Firms are taking steps to mitigate the impact on customers and clients, but the report warns this is unlikely to address the problem in the time remaining without regulatory support.
"Ignoring the question of contract continuity post-Brexit is to play a dangerous game of chicken with the finances of customers across the whole of Europe," TheCityUK CEO, Miles Celic, said.
"Without a viable solution, millions of people could be left without a safety net. This must not be sucked into the Brexit negotiations. It is a non-political issue and needs a non-political solution."
It is thought that contract continuity could impact insurance, pensions, derivatives contracts, credit facilities, and possibly general business contracts, prime brokerage and custody arrangements.
Some of these contracts will require special regulatory intervention to be transferred, as well as time-consuming customer interaction and clearance.
There are also worries that many European regulators will need to deal with products and services they have no experience with, and may need to take on more capacity and train additional staff.
The report argues that any solution will require a coordinated UK/EU response involving the public and private sectors, and that affected contracts must be grandfathered, potentially until maturity.
This could be achieved through a bilateral agreement between the UK and EU, supported by regulatory co-operation, or by separate but consistent regulatory action or legislation in each jurisdiction.
Grandfathering contracts could also be achieved via the final EU Withdrawal Agreement, with any of these solutions requiring ongoing cooperation between UK and EU regulators post-Brexit.
"While firms are doing everything they can, this is not a problem that businesses can fix alone and requires a coordinated UK/EU approach," Celic continued.
"Without it, people and businesses across Europe could be left dangling over a cliff edge following Brexit."