Conservative Leader Andrew Scheer is pushing for an emergency Commons committee meeting in the wake of a massive personal data breach at the Desjardins Group — believed to be one of the largest ever among Canadian financial institutions.

Last month, the Quebec-based bank revealed that an employee with "ill-intention" collected information about nearly three million people and businesses and shared it with others.

Desjardins flagged a suspicious transaction to Laval police in December, but officials said it took several months for them to understand the scope of the scheme.

On Monday, Scheer put out a statement saying he's asked his party's public safety critic, Quebec MP Pierre Paul-Hus, to reach out to the chair of the public safety and national security committee to arrange an emergency meeting for as early as this week.

The House of Commons has risen for the summer break, so a meeting likely would require some MPs to return to Ottawa.

The committee's chair, Liberal MP John McKay, said he's heard also from government MPs on the committee who want to meet soon to talk about the Desjardins breach.

"Normally we'd start with a meeting to agree to have a meeting, but I'm hoping to skip that step and arrange a meeting with substance, with witnesses," he said, adding he "personally" would like to bring the committee together next week.

"I don't know if we can pull it off, but I've asked both the government and opposition members for witness lists."

The leaked information includes names, addresses, birthdates, social insurance numbers, email addresses and information about transaction habits.

Tens of thousands of people already have signed a petition asking for new social insurance numbers in the wake of the breach.

"We must act quickly to help the 2.9 million Desjardins members affected by the theft of their personal data. This situation is unacceptable," said Scheer in the statement.

"The federal government must put measures in place to ensure that this situation never happens again."

Scheer said he wants the committee members to look into whether issuing new social insurance numbers is a viable solution for Desjardins members and ways to prevent future data breaches.