Wightlink's "tourists over suppliers" policy is having a knock-on effect on Isle of Wight businesses, it's claimed.
Island firms say the ferry company is telling suppliers attempting to book journeys: "holidaymakers get priority".
Wightlink has told Isle of Wight Radio it is "surprised" by the allegations, and is working with all freight customers to ensure they receive the best service possible.
One of the businesses affected, Whitwell Garage, says deliveries aren't as frequent as they once were, and the few Portsmouth to Fishbourne sailings that are secured depart at "ridiculous" hours.
Kay Wells, who works at the garage, says it has left staff short of parts and unable to fix vehicles. She said:
"We've had lots of difficulties. Two of our deliveries come from the mainland. All through the pandemic they've come over every single day and now we're getting two days a week.
"They're having silly sort of times like 6.30am in the morning to come over and 12am at night. So not within their working hours."
Whitwell Garage, a Ford dealership, is not the only Island business to have been affected.
Mark Brading, General Manager at Wiltons of Shanklin, says some supplier sailings have been re-routed to Lymington, or cancelled altogether.
During lockdown, he says, Wightlink's service was "really good", but he claims that has now changed:
"It's not really acceptable."
"The worst case scenario for me, in the industry we're in, is if I'm trying to get a car out the door on Friday and the item doesn't arrive for me then I have an unhappy customer in a courtesy car who is going to be in that car all weekend until Monday at the earliest when I can obtain it, fit it in the car and give it back."
As the school holidays approach, Kay anticipates the problem will get worse before it gets better.
Although she says it's "brilliant" tourists are coming here, she thinks it's Islanders who are being made to suffer because of it.
"[Our suppliers] usually come Monday, Wednesday and Fridays to us because they couldn't get the ferries every day and now they've had to change to Tuesday's and Thursday's because they couldn't get the ones on Monday, Wednesday and Fridays, Kay said.
"If you're on holiday and you break down, and you want to bring your car in to get it fixed we can't do fix it because we can't get the parts over here."
The withdrawal of Wightlink's Victoria of Wight service has already led to "chaos" for those trying to book sailings.
Last month (June) Isle of Wight Radio reported how passengers had faced cancelled journeys, unavailable sailings and hour-long phone calls.
A spokesperson for Wightlink said:
"Wightlink is surprised some freight customers claim they are being unfairly treated.
"The temporary withdrawal of Victoria of Wight has caused some issues with capacity for all customers, especially on busy days, but the sales team is working with all freight customers to make sure they receive the best service possible."
Wightlink has told Isle of Wight Radio it will contact affected businesses.