Lawyers representing Spanish policyholders of Independent Insurance have written to the Financial Services Authority (FSA), asking what it has done to prevent another UK collapse.
The lawyers fear that European businesses may be left without cover or compensation if there is another collapse.
Solicitor Inka Piegsa-Quischotte said her clients felt let down by the UK government and the FSA.
She represents construction companies, textile manufactures, retail outlets, printers, hauliers, sports
venues and hotel chains that were Independent policyholders.
Independent, which collapsed in June last year, had sold its policies through Spanish brokers instead of forming a separate Spanish entity.
"Policyholders fear, as other UK-based insurance companies have followed the example set by Independent, it's possible their fate could be repeated," Piegsa-Quischotte said.
She said she had written to the FSA previously, but its reply was "far from satisfying".
"This time I have asked again what is planned to be done to prevent a thing like this happening again," she said.
Piegsa-Quischotte said she expected to receive a reply from the FSA within a month.
The Financial Services Compensation Scheme (FSCS) will not compensate Spanish commercial policyholders, because it does not consider their policies to be "UK policies".
This means they are not covered by the Policyholders Protection Act  or the Employers' Liability (Compulsory Insurance) Act .