FERRY operator CalMac has defended its stance as a union prepares for a ballot of staff over strike action.

CalMac union RMT have ramped up the pressure on the company to enter ACAS talks over the current pay dispute‎ and to "get serious" about reaching a negotiated settlement that properly recognises and rewards the staff operating the lifeline ferry services.

Scotland's biggest ferry union says they were contacted by the arbitration and conciliation service ACAS following media reports of a trade dispute between the union and CalMac.

RMT said they they immediately accepted the approach but claim CalMac rejected the services of ACAS and said they "seem determined to stick with their intransigent position of refusing to recognise that their hard working loyal staff deserve an acceptable pay".

READ MORE: 'Scrooged': CalMac strike threat as anger erupts over pay dispute talks breakdown

Robbie Drummond, CalMac managing director said: “We have made a fair and reasonable offer to staff reflecting the cost of living. We remain open to dialogue with our four unions at any stage.”

Pay talks broke down two weeks ago after the state-owned ferry operator refused to increase their offer despite posting a pre-tax profit of £7.1m last year.

TSSA also rejected what was called a “derisory” pay offer of 0.5%.

RMT general secretary Mick Cash said: “ It’s extremely disappointing and unfortunate that Calmac will not engage in a meaningful and productive manner to find a mutually agreeable solution to this dispute.

"I have informed the company that my union remains available for talks to avert any dispute and despite this they rejected the offer from ACAS to get involved and work with all parties to lift the potential of a dispute that would be damaging to the local economy and bring unnecessary additional stress and pressure to the islanders.

"I would urge the senior management at Calmac to get back round the negotiating table in an honest attempt to reach a settlement. If this means they need to make the justifiable case to the Scottish Government to reach agreement on a fair and reasonable pay award for their workforce then they need to get on and do exactly that.”

TSSA says CalMac made two offers to the unions.

The first was a one year deal of 0.5%. The second was as a two year deal, where workers would get a 0.5% rise in the first year and a retail price inflation rise in year two. The union said both offers were rejected overwhelmingly.