Amid a pay war within his own 2020 presidential campaign, Bernie Sanders will limit the amount of time his organizers can work to guarantee that no one is making less than $15 per hour — a wage the senator has demanded should be the federal minimum.

On Thursday evening, The Washington Post reported that some members of Sanders’ campaign have been lobbying to raise their wages. Field organizers say they make a salary of $36,000 annually but work 60 hours per week, which is an average of $13 per hour.

Unionized workers planned to send a letter to campaign manager Faiz Shakir which read that “many field staffers are barely managing to survive financially, which is severely impacting our team’s productivity and morale.” Some employees, they said, had even left the campaign as a result of the low pay.