The company named May 17th as the earliest date for return – after initially suggesting that the vessel could be back on the Stornoway-Ullapool route by the end of the month.
Meanwhile the Western Isles Labour candidate Shaun Fraser – who said last weekend that his own information pointed to the Loch Seaforth being out of action for at least six weeks – claimed islanders had been “repeatedly misled” about the availability of a back-up vessel.
Mr Fraser said he had seen documentary evidence that Scottish Ministers and CMAL were told last November that the mv Pentalina was available for charter from Pentland Ferries and that this had not changed in the meantime.
He challenged the sitting MSP, Alasdair Allan, to say if he had ever made any independent inquiries about the availability of the Pentalina or any other charter vessel “while the fragile economy of his constituency is falling apart”.
Mr Fraser said: “It is crucial to remember that this crisis did not begin with the
Loch Seaforth breakdown. Barra and South Uist have been suffering for months and the Pentalina could have gone a long way to resolving that issue.
“SNP Ministers are still in office but are now in hiding. They must tell the people of the Western Isles why the Pentalina was not chartered”.
Mr Allan said: “Despite the fact that MV Pentalina would not be available until next month, I believe that there is clear need for her – or any other suitable vessel - to be chartered for CalMac routes.
“We are heading into what should be a busy time with families reuniting after lockdown and tourism businesses getting off the ground again. We need an additional vessel to ensure there is enough resilience in the fleet to get through the summer without any major interruptions”.
Mr Allan said that he had spoken to CalMac today about the need to charter a vessel and hoped “that the opportunity is taken to find a solution”.
The Liberal Democrats also pitched into the issue. Their lead candidate in the Highlands and Islands, Alan Reid, said: "Scotland's ferry network is stuck in the past. Island and peninsula communities have been let down time and time again by SNP ministers who make big promises, stick around for a photo opportunity then vanish into the distance.
"That's no way to treat what are lifeline links for many people. The incompetence of SNP ministers in Edinburgh is like a lead weight holding back communities.
"Local authorities and transport campaigners have long been calling for an overhaul of how our ferry network is handled and I can understand their frustration at being ignored. As we recover from the pandemic it's time to get Scotland's ferry network ship shape."
The managing director of Caledonia MacBrayne, Robbie Drummond, said: “We are working closely with local businesses to make sure that all demand for travel is being met, and I am most grateful to them for their support, patience and understanding as we deal with this situation.”