CIBC is facing a $600 million class action lawsuit, which alleges that the bank has not given employees the paid overtime they are owed.

The action covers thousands of current and former non-management, non-unionized employees who are or were tellers or other front-line customer service employees working at retail branch offices across the country.

It is the largest unpaid overtime suit—which still needs to be certified as a class action—ever launched in Canada. “And if successful,” says Douglas Elliott, a partner with Toronto law firm Roy Elliott Kim O’Connor, “it will result in the bank paying as much as tens of millions of dollars in unpaid overtime to its lowest paid employees.”

The representative of the class action is Dara Fresco, a CIBC teller who has worked for the bank for nearly 10 years. “The average overtime I am required to work ranges from two to five hours a week,” she says. “Even though we complete time sheets, I am discouraged from recording the extra time I in fact worked.”

Banks are regulated by the Canada Labour Code, which specifically states that federally incorporated business may not require or permit non-management employees to work beyond eight hours a day or 40 hours per week without paying overtime, says Louis Sokolov, a partner with Sack Goldblatt Mitchell.

In a statement, CIBC says: “with respect to overtime, we have a clearly defined policy as to how we compensate our front line retail branch employees that exceeds legislative requirements in Canada.”

To comment on this story email craig.sebastiano@rci.rogers.com.