It's not about having an agreement with you. It's about the company and the union having an agreement with each other and the company just trying to discard it to undercut workers' rights to collectively bargain. The government is just stepping in to force companies to negotiate in good faith rather than exploit workers' desperation.

I can guarantee you that there are companies that want to hire you for $2 per hour with no overtime and a minimum required schedule of 80 hours per week. The government is "stopping you from working" for them too.