Former Vice President Joe Biden wrote a letter to the head of Station Casinos last week calling on the company to immediately begin negotiating with workers at two of its properties who voted to join the Culinary Union more than a year and a half ago.

Biden told Station Casinos CEO Frank Fertitta in the letter that it is both “deeply troubling” and “unlawful” for a company to fail to recognize the results of legitimate union elections, such as the ones at Green Valley Ranch and the Palms Casino. He called on Fertitta to allow employees of the two properties to begin negotiating for health care, benefits and other employee protections.

“These workers have earned their seat at the negotiating table and they are legally entitled to recognition,” Biden said.

The former vice president is far from the first Democratic presidential hopeful to weigh in on the fight between Station Casinos and the Culinary Union, but he appears to be the only one to have done so by penning a formal letter to the company’s CEO. Over the summer, Vermont Sen. Bernie Sanders ignited a wave of tweets from candidates — including Biden — calling on Station Casinos to negotiate with Palms employees and voicing their support for the casino workers.

Supporting the Culinary Union — and their 60,000 members in Las Vegas and Reno — in the unionization fight could prove helpful for the Democratic presidential hopefuls seeking to clinch a victory in the state’s first-in-the-West caucus in February. The politically powerful union, known for its impressive organizing chops, has a reputation of turning the tides of elections in the Silver State and could prove decisive in helping a candidate win the caucus should it decide to endorse.

In the letter, Biden praised the Culinary Union as a “critical lifeline” for casino workers in Nevada and said that it has brought “significant improvements to the state’s gaming and tourism industry.”

“Station Casinos, its employees, and its properties will only benefit from a strong relationship with organized labor in Nevada,” Biden said. “As required by law, Station Casinos should immediately recognize the [National Labor Relations Board] elections that have taken place and, without unnecessary delay, come to the negotiating table in good faith with Station employees at any property that chooses to unionize.”

Biden also hinted the political dynamics in play in the fight, with Culinary’s reputation as Democratic booster and the company’s owners known as frequent donors to Republican candidates.

“This isn’t about partisan politics — it’s about what’s good for your workers, your business and Nevada’s economy,” he said.

Station Casinos has been challenging the results of the unionization elections at Green Valley Ranch and the Palms Casino in November 2017 and April 2018, respectively. But the National Labor Relations Board has since ordered the company to begin negotiating with its workers at the two properties.

Station Casinos did not immediately respond to a request for comment on the letter.

Last month, Fiesta Henderson became the seventh Station Casinos property in Las Vegas to have its workers vote to unionize and the third just this year. Workers at Boulder Station and Palace Station were the first to unionize in September 2016 and March 2017, respectively, and are the only two properties whose unionized employees have been recognized by the company, though neither has a contract yet.

Biden has a longstanding relationship with the Culinary Union built during numerous trips out to the Silver State when he was vice president, but it hasn’t been all smooth sailing between the two this cycle.

A CBS News article over the summer revealed that Biden had taken $5,600 in donations from one of Station Casinos’ board members and a prolific Democratic donor, Dr. James Nave. In the wake of that revelation, Culinary Secretary-Treasurer Geoconda Arguello-Kline called on all Democrats to return donations from Station Casinos executives, but Biden’s campaign hasn’t budged.

“We’re proud of all the contributions we’ve received from Nevadans of all walks of life and from all over the state who believe in Vice President Biden’s vision,” Vedant Patel, Biden’s Nevada communications director, said in a statement, asked whether the campaign had returned the donations.

Nave and other Station Casinos board members are copied on the letter.

Massachusetts Sen. Elizabeth Warren also had a misstep with the union when two of her advance staff members crossed the picket line during hotel stays at the Palms in May and June. After it was discovered, Warren apologized and promised that it wouldn't happen again.

Read the letter below:

Update 10-8-19 at 4:02 p.m. to correct that employees at Boulder Station and Palace station do not yet have contracts but have been recognized by Station Casinos.