LAS VEGAS (CBS/AP) — Union members are calling the public to boycott Republican presidential nominee Donald Trump’s businesses nationwide because he isn’t negotiating a contract with the more than 500 eligible workers at his high-rise Las Vegas hotel.

UNITE HERE announced the effort this week. The group is the parent organization of the Culinary Union, which represents about 57,000 Las Vegas-area hospitality workers.

READ MORE: Knife-Wielding Man In Custody Following Standoff With Police in South San Jose

“After a disgraceful anti-union campaign against their own workers, the hotel still refuses to negotiate with their employees,” Geoconda Arguello-Kline, the top officer at the Culinary Union, said in a statement. “We call on allies and workers to stand in solidarity in a national boycott until Donald Trump, the `Great Negotiator,’ comes to the table.”

Donald Trump's book is seen for sale at a shop inside the Trump International Hotel in Las Vegas, Nevada.  (JOSH EDELSON/AFP/Getty Images)

Donald Trump’s book is seen for sale at a shop inside the Trump International Hotel in Las Vegas, Nevada. (JOSH EDELSON/AFP/Getty Images)

Workers at Trump’s hotel voted in December to unionize, but management hasn’t started bargaining with them. Experts say it could take years, and court action, before management is forced to come to the table.

The Culinary Union and its partners have held large marches outside the resort to pressure the company to act, and events supporting the boycott are scheduled in Waikiki, San Francisco and Chicago in coming weeks.

READ MORE: Fremont Woman Killed in New York After Being Shoved In Front of Approaching Subway Train

Union officials say workers at Trump’s hotel earn about $3 less per hour compared with their counterparts on the Las Vegas Strip.

Company and campaign officials didn’t immediately respond to a request for comment. In an interview with the Las Vegas Sun earlier this month, Donald Trump Jr. said he wasn’t aware of any negotiations set to start soon.

“If you look at our history, you’d see a history and decades of negotiation,” the presidential candidate’s son told the newspaper. “So we’ll see what happens. Everything is a case-by-case basis.”

MORE NEWS: COVID: Unions Push Back On State Guidelines Allowing Health Care Workers With Coronavirus To Return To Work

© Copyright 2016 The Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed.