A pair of top-tier 2020 Democrat candidates are threatening not to participate in next week’s presidential primary debate in Los Angeles as a labor dispute embroils the campus set to host the event.

Sens. Bernie Sanders (I-VT) and Elizabeth Warren (D-MA) both said Friday that they would not cross the picket lines of Loyola Marymount University employees to enter the sixth debate, co-hosted by PBS NewsHour and Politico, next Thursday.

“I stand with the workers of @UniteHere11 on campus at Loyola Marymount University fighting Sodexo for a better contract,” Sanders wrote on Twitter. “I will not be crossing their picket line.”

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. — Bernie Sanders (@BernieSanders) December 13, 2019

“@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,” Warren tweeted. “I will not cross the union’s picket line even if it means missing the debate.”

.@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. — Elizabeth Warren (@ewarren) December 13, 2019

UNITE HERE Local 11, a labor union which represents over 100 food service staff at the college, said it has thus far failed to reach a collective bargaining agreement with Sodexo, a France-based catering and facilities management corporation.

“The Local 11 began talks with Sodexo in March, but said the company last week canceled scheduled contract negotiations after workers and students began picketing on campus in November,” a Sodexo spokesperson said in a statement obtained by Politico.

It is unclear whether both parties will strike a deal before the debate.

Other 2020 candidates, including former Vice President Joe Biden, have not publically said whether they would join Sanders and Warren in skipping the debate.

The debate was originally scheduled to take place at UCLA, but was moved following a request from the American Federation of State, County and Municipal Employees over an ongoing labor dispute.

Update: Biden, South Bend Mayor Pete Buttigieg, Sen. Cory Booker (D-NJ) and others have threatened to ditch the debate unless the labor dispute is resolved before Thursday.

I won't be crossing a picket line. We’ve got to stand together with @UniteHere11 for affordable health care and fair wages. A job is about more than just a paycheck. It's about dignity. https://t.co/nn4tb5q8wt — Joe Biden (@JoeBiden) December 13, 2019

I take the debate stage to stand up for workers’ rights, not to undermine them. I stand in solidarity with the workers of @UNITEHERE11 at Loyola Marymount University and I will not cross their picket line. — Pete Buttigieg (@PeteButtigieg) December 13, 2019

The dignity of work must always be promoted and protected. I support @UNITEHERE11 in their fight for fair wages and benefits. No Democratic candidate should cross the picket line. — Cory Booker (@CoryBooker) December 13, 2019

As I said at my event with labor leaders here in Miami, I will not cross the picket line and I will stand with @UniteHere11 to fight for the dignity of work. — Amy Klobuchar (@amyklobuchar) December 13, 2019

I won’t cross the @UniteHere11 picket line to attend next week’s debate. We must live our values and there is nothing more core to the Democratic Party than the fight for working people. I support @UniteHere11 in their fight for the compensation and benefits they deserve. — Andrew Yang (@AndrewYang) December 13, 2019