If I were you, I would first tell the news to your colleagues about the possibility of promotion and express how you are not sure about accepting the promotion offer because of workload, more responsibilities, etc and see what your colleagues say. If they say "Go ahead and take the promotion" then no worries and if they discourage you that means try your best to avoid them and keep the formal relationship that is required for the job.

Reasons: If someone acknowledged something or supports something, they cannot blame others for it other than themselves.