One of the country’s largest public-service unions endorsed former vice president Joe Biden on Monday, further consolidating a key part of the Democratic coalition around the leader in the party’s nomination contest.

The 35-member executive board of the American Federation of County, State and Municipal Employees met Monday afternoon, speaking by teleconference because of the coronavirus outbreak, and voted unanimously to support Biden.

“We believe that it’s time to prepare to work like hell for Joe Biden and to bring the party together so we’re unified behind one candidate,” AFSCME President Lee Saunders said in an interview with The Washington Post.

Members of the board used “a lot of colorful language” to describe how President Trump’s policies have hurt workers, particularly in the Midwest, according to a person familiar with the proceedings who was not authorized to discuss a private meeting.

Saunders last spoke with Biden in late February, around the time of the Nevada caucuses, but he said the union and Biden’s team have been in frequent contact. He added that Biden’s organization has been receptive to the union’s policy suggestions.

“We’ve always had good conversations, and now’s the time to coalesce around his candidacy,” Saunders said. “I really believe that it’s very, very important for unions and other organizations that play in the political arena to come together and to unite behind the one candidate.”

The move comes at an unusual political moment. Biden has all but wrapped up the Democratic nomination. If influential groups continue to publicly embrace Biden it could send additional signals to Sen. Bernie Sanders (I-Vt.) that he should formally withdraw, something many Democratic leaders privately want him to do.

Asked if Sanders should leave the campaign, Saunders said that it is “his own personal choice” but added, “I think he understands the importance of bringing the party together and unifying, because our number one priority right now is to defeat the present occupant in the White House.”

Two other major service unions, the National Education Association and the American Federation of Teachers, also recently backed Biden. The fourth, the Service Employees International Union, has so far not endorsed in the Democratic primary, though some of its local affiliates have backed Sanders.

Biden also has the support of 13 former 2020 presidential candidates.

In the 2016 Democratic primary, AFSCME backed Hillary Clinton early in the process, drawing ire from members who supported Sanders. This time, union officials waited much longer and conducted several membership polls to determine which candidate had the most support.

The most recent poll showed AFSCME members backing Biden by a 2-to-1 margin, Saunders said. The union represents about 1.4 million workers, including nurses, corrections officers, school bus drivers and child-care providers.

Saunders declined to say exactly what type of support Biden can expect from the union. Labor groups typically provide an army of organizers who can go door-to-door for a candidate, but with the coronavirus pandemic, the union is focusing more on digital organizing.

Biden has faced criticism in recent days that he is keeping a low profile at a time when he needs to speak out. His campaign recently constructed a TV studio in his home so he can more frequently communicate with the public, and he gave brief remarks from the new facility Monday morning.

“His people are putting together a strategy to move forward,” Saunders said. “He is going to have to be visible, obviously. I mean, we’re in a crisis situation right now.”

Sanders has sent mixed signals about the future of his campaign, with some of his confidants urging him to stay in the race if only to collect additional delegates and have a stronger voice in shaping the party’s platform.