Ferry operator Caledonian MacBrayne (CalMac) has provided no new support for the Firth of Clyde’s Arran route in a shake-up of services after the biggest and oldest vessels in Scotland's ageing lifeline ferry network were sidelined for nearly three months.

The 1,000-passenger MV Caledonian Isles, which for 31 years has served on the Arran route, is one of the busiest on the coast of Scotland, is due to be replaced but has been out of action since going for an overhaul at the start of January, with repairs expected to cost £5 million.

CalMac has warned of the disruption across the Clyde and Hebrides networks as a result of steelwork issues with the hull of the ageing Caledonian Isles. The 5,521-tonne ferry is due to be replaced by one of the two wildly overbudget and delayed hybrid-powered ferries being built at Ferguson Marine, Port Glasgow.

The Isle of Arran Ferry Committee said it was pushing for contingency plans over the latest problem to hit CalMac's ageing fleet. The Scottish Government’s new transport minister was expected to consult with CalMac managers to find out what action can be taken to support the Isle of Arran service linking Brodick and Ardrossan on the mainland.

The company said it is to maintain the new shake-up on the route with the current single vessel, the 41-year-old MV Isle of Arran. In addition, the possibility of the £1 million-a-month emergency Scottish Government-chartered catamaran ferry, MV Alfred, supporting Arran services from March 9 when it returns from its annual overhaul is being evaluated.

More TheHerald Scotland reports on the affected south-west service.