All seven Democratic presidential candidates who have qualified for next week's primary debate in Los Angeles are now threatening to boycott it over a labor dispute.

Sen. Elizabeth Warren, a leading canidate, first signaled she wouldn't cross the picket line as workers represented by Unite Here Local 11 planned to protest outside the debate hall Thursday, the day the event's scheduled to take place. Soon the other six candidates followed.

The union represents 150 cooks, dishwashers, cashiers, and servers who work on Loyola Marymount University's campus, but are employed by the subcontractor Sodexo.

Sen. Elizabeth Warren was the first Democratic candidate to say she wouldn't cross a picket line in order to participate in Thursday night's primary debate in Los Angeles

The next Democratic primary debate is to take place on the campus of Loyola Marymount University in Los Angeles, which is the second school to have been picked to host this paricular debate

Workers from Unite Here Local 11 are seen protesting Sodexo, which is a subcontractor that works with the university where the debate is to be held

Sen. Bernie Sanders, another top progressive in the race, followed Warren's lead - as did the other five Democratic contenders who are eligible to take part in the Thursday debate

Local 11 has been negotiating with Sodexo since March and picketing since November.

Planned contract negotiations between the two sides were abruptly called off last week, according to a media release from the union.

'We had hoped that workers would have a contract with wages and affordable health insurance before the debate next week. Instead workers will be picketing when the candidates come to campus,' Local 11 co-president Susan Minato said in a statement put out Friday.

In the hours following, all seven candidates who made the debate stage sided with the union.

'@UNITEHERE11 is fighting for better wages and benefits—and I stand with them. The DNC should find a solution that lives up to our party's commitment to fight for working people. I will not cross the union's picket line even if it means missing the debate,' Warren vowed.

The Democratic hopefuls used Twitter to stand in solidarity with the union, which is fighting with Sodexo the company they directly work for

Sen. Bernie Sanders, another top progressive candidate, soon chimed in.

'I stand with the workers of @UniteHere11 on campus at Loyola Marymount University fighting Sodexo for a better contract. I will not be crossing their picket line,' the Vermont senator declared.

South Bend Mayor Pete Buttigieg joined the chorus.

'I take the debate stage to stand up for workers’ rights, not to undermine them,' he tweeted.

As did former Vice President Joe Biden, Sen. Amy Klobuchar, billionaire activist Tom Steyer and businessman Andrew Yang.

Just seven Democratic candidates of the 15 who are still running qualified for the December debate.

Rep. Tulsi Gabbard, who needed one more poll to get on the debate stage, already said she wasn't planning on going.

Loyola Marymount is the second location for the debate, as a labor dispute at UCLA already moved the Los Angeles debate once.

Sanders will be making the trek to Los Angeles with way, as he announced a rally for the Saturday after the debate alongside Rep. Alexandria Ocasio-Cortez, who officially backed his bid in October.

Sanders and AOC will then travel to Las Vegas for a second Saturday appearance together.