Ferries provide lifeline services to the islands

About 450 members of the Rail, Maritime and Transport Union who work for the company are to be balloted on industrial action on Thursday.

If the vote backs action, strikes could be staged by the end of August, affecting 13 of the publicly-owned company's 30 ships.

Calmac says it has offered a 3.5% pay rise, but union officials are unhappy that 1% of the deal is performance-related.

The firm said it was due to meet officials from the RMT on Friday.

But the union said it would only meet the company if it improved its 3.5% offer and stressed no firm date had been set for talks.

Calmac spokesman Hugh Dan MacLennan said: "We have made what we believe to be a reasonable and proper offer.

We have no desire whatsoever to cut off any parts of Scotland and indeed the island communities Steve Todd RMT

"If they were to take the action... it would affect up to 50,000 people living in our island communities and as everyone knows, this is the height of the summer season and it would have the effect of crippling most of the fleet."

He pointed out that there would be no impact on small ferries, which are covered by a separate agreement.

Steve Todd, the RMT's Scottish organiser, said it was not yet certain that Friday's meeting with management would take place.

"We need to know what the company wants to lay on the table and we need also to know, are they going to remove this performance-related pay element?

"We did warn the company back in January that we were not interested in PRP. Obviously to me, the company are not interested in listening to what we are saying."

Strike action 'close'

Asked how members would vote in a ballot, Mr Todd described strike action as "closer this year than we have been for a number of years".

"The company needs to take into consideration the delay in giving us the actual pay claim and the way it is being pushed through at the moment.

"We have no desire whatsoever to cut off any parts of Scotland and indeed the island communities and I understand what that means for the communities, having lived and worked in Scotland for the last 15 years."

The last time Calmac ferries were hit by strike action was in 2001, when more than 100 members of the RMT stopped work for a week.

The dispute was in protest at a reduction in the working week for pier hands and sea-going staff.

It resulted in the cancellation of services to Arran and Bute.