Bus Vannin says it is likely that there will be no buses running on the island this evening.
Unite the Union members have started the first day of a strike over pay and conditions.
What service there has been today has been today by casual bus drivers with support from supervisors.
Bus Vannin warned: “However, with no more staff coming forward those casual drivers will be nearing their legal maximum driving hours as we move in to the latter period of the day, the team will utilise what capacity remains to cover the main corridors, but we believe that by early evening we may no longer be able to deliver any services.”
“We are therefore strongly advising our customers to look to make alternative travel arrangements for today.”
It added that additional people have made themselves available tomorrow so a service will run on Sunday.