Walmart CEO calls on Congress to increase "lagging" federal minimum wage

• Sanders also used his time at the meeting ask Walmart for a seat on the company's board for hourly workers, complaining that employees still have to rely on food stamps, Medicaid and public housing to make ends meet.

By the numbers, according to McMillon:

• Walmart has increased starting wages by 50% over the last 4 years.
• The retailer pays an average of $17.50 per hour in wages when bonuses and benefits to associates are factored in.

The state of play: Amazon, one of Walmart's biggest competitors, announced last year that it would hike the minimum wage for its 350,000 employees to $15 an hour. At the time, Sanders said, "I want to give credit where credit is due."

Worth noting: McMillon's salary last year was $23.6 million — more than 1,000 times the median salary of its hourly workers, according to a Washington Post analysis of company filings.

Go deeper: Why Bernie Sanders is crashing Walmart's annual shareholders' meeting