Desjardins Group is facing a legal backlash after a class-action lawsuit has been initiated in connection with a data breach affecting nearly three million members.

The proposed class action, filed in Quebec Superior Court on Friday, alleges the co-operative financial group was negligent in safeguarding its members’ personal and financial information.

Desjardins chief executive Guy Cormier said yesterday a former employee shared the personal information of more than 2.9 million members with third parties outside of the organization.

The data includes social insurance numbers, names and birthdays, and affects 2.7 million individual members and 173,000 business members.

Applicant Hugo Langlois says the fact that additional security measures were implemented following the internal breach suggests Desjardins failed to live up to its obligations and owes affected members $300 each, plus punitive damages.

On Friday, Desjardins extended its offer to pay for a credit monitoring plan and identity theft insurance for affected members to five years, up from the 12 months announced Thursday.