Bus Vannin says more than 20 of its services may be called off today.
On Facebook, the Department of Infrastructure's public transport division says issues with illness and short-staffing continue throughout the day.
As a result, 21 services are at risk of cancellation between 10am and 10pm.
They including links between Douglas and Ramsey, Onchan, Port Erin, Laxey and Jurby.
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