A row has erupted as a key Scots port has become unusable for ferries meaning that a CalMac's move to stay away due to safety issues will last for at least another week.

Ardrossan port owner Peel Ports are having to carry out repairs to a berth having already shut down the other Irish Berth permanently over safety concerns.

Now CalMac has confirmed that the move to Troon for lifeline services to Arran, one of Scotland's busiest routes, will continue till at least Thursday of next week.

It said that the repairs are to the berth's fender and that it had been advised they won't be complete till Monday at the earliest.

It means a curtailed temporary timetable will remain in place.

And they have warned users that services from Troon will continue to take pre-booked customers only, as it does not have any ticketing services available.

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The three return sailings a day will continue until Thursday.

CalMac started operating from Troon last week after trial berthing of MV Isle of Arran, the only ferry carrying passengers to and from the island.

There has been concern that it is the first step to a permanent move for the services, with the £1m-a-month Scottish Government-chartered emergency vessel MV Alfred beginning a freight service from there as it was unable to use the Irish Berth.

Alfred is now being redeployed away from Arran from Monday to serve Uig on Isle Of Skye, Lochmaddy on North Uist and Tarbert in Harris between Monday 12 and Friday 16 February. This deployment is to allow MV Hebrides to travel to dry dock for planned annual overhaul.

Sam Bourne, chairman of the Arran Ferry Action Group said the move ushers in "more disruption and limited capacity".

The Herald: MV Alfred is now on the Arran route

"Having damaged fenders makes Ardrossan unusable in any weather. "It's unbelievable and yet entirely predictable!

"The fact that the ageing infrastructure at Ardrossan is failing should not be a surprise to anyone. This all highlights the fundamental lack of reliability and resilience in our lifeline ferry service through reliance of life expired vessel and port infrastructure. We are now basically one failure away from no service at all."

The move to Troon has already been hit with difficulty, with some complaining about not being able to get tickets for the crossing.

It emerged early Thursday afternoon that all sailings including freight operated by MV Isle of Arran and MV Alfred to Brodick were cancelled and remained out on Friday. A limited time timeable was due to operate on Saturday and Sunday.

Users say any long period based in Troon would mean travelling times rising from 55 minutes to an hour and 20 minutes and concerns have been raised over a potential cut in sailings.

A ferry user group official said: "It is yet another ferry shambles that CalMac have to try and handle and I pity the staff who are having to deal with angry customers."

It comes as the 30-year-old MV Caledonian Isles the second vessel that serves on the Arran route, and is due to be replaced, has been out of action since going for an overhaul at the start of January.

It was sidelined for over three months with further steelwork and engine difficulties this time last year. Further steelwork problems were attributed to a further period spent in the yard in early 2022.

The vessel has been found to have had major technical problems and is now not expected back till at least the end of next month.

Users have been told that the vessel needs "extensive steelwork" leading to concerns that it is suffering rust issues.

MV Caledonian Isles is to be moved to the Cammell Laird yard facility in Liverpool for repairs and there is a race against time to get it available in time for the summer timetable to kick in on March 29. CalMac has said it is expected to be sidelined for four to six weeks.

But user groups have been told that a true assessment and timeline will only be known in the coming weeks, once the vessel has been moved and a full assessment is made.

The Scottish Government-owned ferry operator made moves to pull out of Ardrossan in the wake of safety issues and adverse weather.

Video: MV Caledonian Isles

They moved to begin trial berthing MV Isle of Arran, the only ferry carrying passengers to and from Arran at Troon.

It began operating on a "temporary" basis from Troon on Thursday in a move that is due to end on Sunday.

The Irish Berth at Ardrossan, which had been used by an emergency CalMac ferry for the key lifeline route to Arran was put out of action on January 18 when the harbour authority ordered all users to cease operations.

Two long-delayed and massively over-budget ferries Glen Sannox and Glen Rosa were due online in the first half of 2018, are now due to serve Arran.

But they are at least six years late, with costs expected to be quadruple the original £97m contract.

Glen Rosa was meant to be delivered to CalMac in August 2018, but that is currently scheduled for May 2025. Glen Sannox, was launched by Nicola Sturgeon nearly seven years ago and is due for delivery in the spring.

But the dates of arrival have been constantly in a state of flux as their construction has been plagued by design challenges, cost overruns and delays.

The Scottish Government has previously confirmed that no decision had been made over whether Ardrossan would remain the mainland port for the Arran service – placing serious question marks over an upgrade project which has doubled in cost.

The full business case for a project to upgrade Ardrossan to allow the two ferries to berth there and take the 'green fuel' LNG remains incomplete. Consequently, the project has still to be put out to tender.

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It is understood there have been issues over how the cost – which in 2022 was estimated at £40m – would be divided between the Scottish Government quango Transport Scotland, the harbour owner Peel Ports and North Ayrshire Council.

The Scottish Government-owned ferry operator CalMac has already been planning to use Troon rather than Ardrossan for the two ferries that will serve Arran. That was when it was hoped that the first of the vessels would be ready for passengers in the Spring of last year.

A CalMac spokeswoman said: “The Arran berth at Ardrossan is unusable at the moment due to broken fendering, and Peel Ports are currently carrying out the necessary repairs. They have informed us that these will not be complete until Monday the 12th at the earliest.

“In response, we have decided to extend the time we are using Troon as an alternative port to Ardrossan until Thursday 15 February. This is due to further predicted adverse weather and allows more reassurance for customers.”