PASSENGERS have been warned to expect severe delays and disruption on Scotland's ferry network after vital repairs to a key vessel were delayed by several weeks.

Caledonian MacBrayne revealed that “complications” to the repair of one its ferries will mean it will “now be out of service for longer than first anticipated.”

As a result of the problems to the MV Clansman, which usually serves Coll and Tiree out of Oban, CalMac is having to reshuffle the major vessels in its fleet again.

Parts of the Clansman’s propulsion system have had to be sent to Denmark for specialist repair.

It comes passengers have already been hit by widespread disruption due to CalMac's ageing fleet.

The average age of ferries serving routes from Arran in the south to Lewis in the north is just under 22 years.

Islay, Harris and Uist have already been hit by disruption, with the Hebridean Isles, one of two ferries that normally serve Islay, already withdrawn to work on the Tarbert and Lochmaddy routes.

Now CalMac has agreed an extension to the Uig triangle ferry MV Hebrides’ operating licence, which was due to enter dry dock, with the Maritime and Coastguard Agency for a further three weeks.

‘We are facing a highly regrettable situation that we need to manage as best we can with the vessels we have. Our first priority is to continue to provide lifeline service to island communities,’ said CalMac’s Managing Director, Robbie Drummond, said: "The overrun of our annual vessel dry dock schedule into the summer season is regrettable and we realise that this set of circumstance is going to impact adversely on some communities which we apologise for.

"However, under the circumstances, the timetable arrangements we have now put in place for the period of disruption are the best options we have available".

CalMac will now be operating to an amended timetable until the return of all major vessels expected by May 31.

The major changes will see the Ardrossan to Arran service revert to a ingle vessel timetable from April 26 supplemented by MV Isle of Arran delivering shared timetable between Brodick and Islay The start of the summer service from Ardrossan to Campbeltown has been postponed Services to Islay will also revert to a single vessel timetable from April 26 supplemented while all Mallaig to Lochboisdale sailings will be cancelled.

Mr Drummond added: "We believe these arrangements will cause the least disruption possible. Through vessel redeployment and timetable amendments we are confident that we can satisfy all demand for services including the extra traffic that will be generated by the Islay Whisky Festival and the upcoming World War I commemorations. Although we realise that communities such as Mallaig, Campbeltown and Armadale will be disadvantaged for a short period, we need to deploy resources where they are needed most."

Western Isles Council last night said it was concerned about the latest ferry disruption to its communities on Uist - with the Mallaig to Lochboisdale route cancelled.

A spokesman said: "This is a matter of concern. Some of our island routes have already faced major disruption and we are not even into the main summer season yet.

"We hope that CalMac rectify these repair issues speedily so passengers do not continue to suffer disruption and there becomes a lack of confidence in the service among tourists - as well as residents - which are vital to our economy."