Another of Scotland lifeline ferries was taken out of action on Tuesday due to a Covid case - with customers advised not to travel to Mull.

The request from taxpayer-owned CalMac on Tuesday came as a row over a new wave of disruption and cancellations over CalMac's ageing fleet raged on.

Ferries across the taxpayer-owned CalMac lifeline vessel network have had to be re-organised with a host of sailings cancelled to try and cover for the loss of 21-year-old MV Hebrides due to an oil leak which is not expected to be resolved for over a week.

MV Hebrides, which can carry 612 passengers and 90 cars was due to be replaced by a new ship, one of two dual-fuel vessels at the centre of a ferry-building fiasco that are languishing in Ferguson Marine shipyard in Port Glasgow on the Clyde.

After a delay of over four years the new ferry, known as Hull 802, is expected in early 2023.

Now it has emerged that as the network tries to adjust to the loss of MV Hebrides, MV Isle of Mull, was put out of action for the second time in a week after a crew member returned a positive Covid test.

It mean four sailings were cancelled on one of Scotland's busiest routes - Oban to Craignure on Tuesday.

In line with the Covid-19 protocol arrangements have been made for the vessel to be deep cleaned upon return to Oban on Tuesday afternoon.

CalMac encourage customers travelling as foot passengers, and who are intending to travel on the cancelled sailings "not to travel to Mull".

The Herald:

The Scottish Government-controlled ferry operator said: "As MV Isle of Mull sailings are cancelled there will be capacity issues which may significantly affect your ability to return to Oban."

Highlands and Islands MSP Donald Cameron MSP, the Scottish Conservatives' shadow constitution, external affairs and culture secretary said yesterday after the latest ferry issues: "The SNP were warned in 2010 they needed to regularly replace vessels in the ferry fleet to sustain the service. It's on them, and no one else."

It comes as further disruption emerged on Monday with the 38-year-old MV Isle of Arran taken out of service after a crew member tested positive for Covid-19.

The loss of MV Isle of Arran meant cancellations on one of Scotland's busiest crossings - Ardrossan to Brodick.

It came back into service on Tuesday, but because of lack of crew the vessel was only dealing with commercial traffic.

Problems with an oil leak on the shaft seals on MV Hebrides, which serves the Uig to Tarbert and Lochmaddy route, were discovered over the weekend and repairs began on Friday. At the time it was thought to be a problem with the exhaust.

It was due to go to dry dock in Birkenhead on Tuesday, and is due to be out of service until September 9. CalMac has warned that this date is liable to change.

READ MORE: Ferry breakdown and Covid cause new CalMac lifeline service chaos

Twenty-three-year-old MV Clansman was shifted to help with sailings lost in the Hebrides area from Tuesday morning - leading to cancellations of sailings on its usual Oban to Colonsay and Barra routes for the next week. Sailings between Coll, Tiree and Barra will also be cancelled on Wednesday, CalMac said.

The Herald:

And the 32-year-old MV Lord of the Isles, one of the biggest and oldest vessels in the CalMac fleet has been tasked with taken up some of the slack on the Oban to Colonsay crossing.

But that has meant cancellations to four sailings a day on the Mallaig, Invernesshire to Armadale on the Isle of Skye route until Sunday. It also means further cancellations to sailings on the route between Mallaig, Invernesshire and Lochboisdale on South Uist.

Passengers that use the Mallaig to Armadale ferry were told that they will be rebooked onto alternative sailings.

CalMac has said that as a result of MV Hebrides being withdrawn from service and vessel redeployment, there is disruption on one of Scotland's busiest services, Oban to Craignure on the Isle of Mull.

They advised there may be longer queues and waiting times at Lochaline and Fishnish.

In the midst of the disruption concerned passengers have continued to complaint at being unable to get through to CalMac's customer relations team.

READ MORE: Tycoon and FM adviser McColl talks of comeback and end to ScotGov control on ferries

It is the latest in a summer of issues with breakdowns and Covid issues involving Scotland's ageing ferry fleet.

The breakdown in April of Scotland's biggest publicly-run ferry MV Loch Seaforth, which operates on the Stornoway to Ullapool route, caused similar disruption across the islands network for seven weeks.

Islanders from Arran to Islay have lodged complaints to ministers about disruption and cancellations to services as the ageing Scottish ferry fleet falters.

While industry experts agree the working life of the ferries is 25 years, 14 of the 33-strong ferry fleet run is older than that, with eight past their 30th birthday.

UPDATE: CalMac said that MV Isle of Mull was back in service on Wednesday morning as normal. The ferry operator said it was operating alongside MV Coruisk. 

It said anyone who was booked onto cancelled sailings were accommodated on other sailings.