Julian Castro, the 2020 presidential candidate who was former President Barack Obama’s Housing and Urban Development (HUD) Secretary, will reportedly allow his campaign workers to unionize.

Jennifer Fiore, a senior adviser for Castro’s campaign, reportedly told the Daily Beast on Monday evening that the campaign has decided to support a union if Castro’s campaign staff decides to organize.

“The leadership of this campaign comes from the social justice movement,” Fiore told the outlet.

The Daily Beast noted that The Campaign Workers Guild, which launched last year, “had some success encouraging and working with unions in the midterm cycle with 24 campaigns and three state party coordinated campaigns ratifying their collective bargaining agreement.”

As the 2020 field becomes more crowded, Democrats running for president could face pressure to allow their campaign workers to unionize to signal that they are progressive enough on labor issues.

According to the Daily Beast, The Campaign Workers Guild’s Julia Ackerly indicated that her group will “be meeting in the coming days to strategize on how best to put pressure on candidates to recognize unions when and if their workers want to form them.”

Ackerly told Mother Jones last year that her group will be calling on “Democratic candidates to practice what they preach,” especially “because for a really long time the culture of progressive campaigns has been exploitative and campaign workers have been denied basic labor protections.”

“We’re starting with Democratic candidates because there is an explicit disconnect between the Democratic platform and how Democratic candidates treat their workers,” she told Mother Jones.