Sen. Bernie Sanders plans to attend Walmart Inc.’s annual shareholders meeting next month to push for the retail giant’s workers to get a seat on the board of directors.

“Walmart workers are sick and tired of being paid poverty wages, while the Walton family is worth over $170 billion,” the Vermont senator and Democratic presidential candidate said in a tweet Tuesday. “I’m honored to have been invited by Walmart workers to demand they have a seat on the company’s board.”

Sanders has long been a critic of Walmart WMT, +0.52% , and last year introduced a bill to improve pay and sick days for workers and cap CEO compensation at big companies, including Walmart.

At the invitation of a group of Walmart’s hourly workers, Sanders will appear at the June 5 shareholders meeting in Rogers, Ark., to introduce a proposal calling for worker representation on the board. Walmart employees have been calling for improvements to wages, benefits and more predictable schedules.

Earlier this month, Walmart disclosed that its store managers make an average of $175,000 a year, while full-time hourly workers make an average of $14.26 an hour. Walmart, which employs about 1.5 million people in the U.S., has been facing increasing pressure to improve wages, after competitors such as Costco Wholesale Corp. COST, +0.68% and Amazon.com Inc. AMZN, +0.66% raised their minimum wages to $15 an hour last year.

Read: U.S. minimum wages are probably at their highest level ever, one economist says

“These workers need and deserve a seat at the table,” Sanders told the Washington Post. “If hourly workers at Walmart were well represented on its board, I doubt you would see the CEO of Walmart making over a thousand times more than its average worker.”

The measure is almost certain to fail. Shareholders have rejected every proposal from employees in the company’s history, according to the Post, and the Walton family controls about half the shares.

“If Senator Sanders attends, we hope he will approach his visit not as a campaign stop, but as a constructive opportunity to learn about the many ways we’re working to provide increased economic opportunity, mobility and benefits to our associates,” Walmart said in a statement.

It is unclear if Sanders will meet with any Walmart executives or board members during his visit.