A row has erupted between CalMac and union members over bonuses and pay.

Talks broke down on Thursday after two days of discussions and the RMT union has now entered into a formal dispute with CalMac.

RMT claims ferry staff will no longer receive a 1.5% annual bonus they have been paid whenever CalMac has made a profit over the last decade.

The union is also unhappy about CalMac's offer of a 1.8% pay increase each year for the next two years, which it says will see wages fall behind the cost of living.

CalMac is "dismayed and disappointed" by RMT's decision to begin a formal dispute.

RMT general secretary Mick Cash said: "It's clear to everyone that our members played a huge role in the campaign that led to CalMac beating off the attempt to wrestle the lifeline ferry services away from them.

"These pay and bonus proposals from management are a kick in the teeth for those loyal and dedicated RMT CalMac members and will be resisted by all means necessary."

RMT claims senior managers and directors could continue to benefit from an annual bonus, although CalMac insists no decision has been made.

The two groups recently worked together to win a new eight-year contract for the Clyde and Hebrides Ferry Service for CalMac.

Managing director Martin Dorchester said: "The offer on the table of 1.8% is nearly double recent average public sector pay increases.

"This is an extremely generous pay offer in the current climate of tight public-sector budget restraint.

"Any moves to disrupt services would be a huge let down for all the people who rely on our services and who backed CalMac staff so vocally and enthusiastically during the tendering process."

He added: "I would urge trade union members to think carefully about the potential damage any industrial action will have on the communities they serve and are part of, just as we are about to start rolling out new innovations that will improve services for all over the long term.

"This is a road no one wants to go down."