AN EXTRAORDINARY public row has erupted over a troubled £97m contract for two new CalMac ferries involving a billionaire adviser to Nicola Sturgeon.

The government-owned body which ordered the vessels flatly rejected claims by tycoon Jim McColl that it was to blame for design changes and therefore liable for extra costs.

Kevin Hobbs, chief executive of Caledonian Maritime Assets Ltd (CMAL), told MSPs that responsibility for the extra costs lay squarely with Mr McColl’s shipbuilding firm.

“We can judge that it will be costing an awful lot more… that is not our problem,” he said.

Mr Hobbs also appeared to take a swipe at Mr McColl, saying pointedly that CMAL had been “extremely honourable” and hadn’t “moaned and groaned” about the contract in the press.

Mr McColl gave an interview to this week’s Sunday Times in which he said he was on the verge of taking CMAL to court over design-related delays.

The ships are being built by Ferguson Marine Engineering, the last commercial shipyard on the Clyde, which Mr McColl’s Clyde Blowers empire bought out of administration in 2014.

The vessels should have been delivered this year, increasing capacity on the Ardrossan to Arran route and Uig triangle, but have been delayed to next summer and spring 2020.

Since the delays first emerged in July 2017, the Scottish Government has loaned Ferguson's £45m of taxpayers’ money to ensure the yard’s continued “viability”.

Amid growing concern at Holyrood over the arrangement, Mr McColl, who sits on the First Minister’s Council of Economic Advisers, put blame on CMAL.

He told the Sunday Times: "The construction process is slower because the ferries are prototypes. Because of this there have been additional costs which we have funded and which CMAL have refused to discuss. This is what has necessitated the loans from the Scottish government. CMAL's attitude has put our business under pressure."

He added: "I'm very frustrated with CMAL. They should have carried out more design and development work on this project before they put it out to tender."

However Mr Hobbs was emphatic that Ferguson's had bid for and signed a “fixed price” design and build contract, and CMAL did not intend to pay any more.

He said: “Ferguson Marine along with everybody else bidding for that contract at the time, they’re private companies, and with a private company there’s risk and reward.

“They signed up to that contract knowingly and willingly, and as far as we’re concerned £97m is what we have to pay.

“We can judge that it will be costing an awful lot more. Our assertion at this particular point in time is that is not our problem.

“That is the problem of a private company that knowingly and willingly bid for these vessels."

He added: “We feel we’ve been extremely honourable. We haven’t gone to the press. We haven’t moaned and groaned.”

Mr Hobbs suggested CMAL might not even pay the £97m, as the contract allowed for “liquidated damages”, or compensation, for missed delivery dates and quality issues.

”There are a number of things at the end of the contract which we will have to weigh up.”

Mr Hobbs also said that although the two “dual-fuel” vessels were the first of their kind built in the UK, they were not new technology, with 2000 such engines bought worldwide.

Mr McColl’s complaint was also challenged by CMAL director of vessels Jim Anderson.

He said Ferguson's had tabled the “outstanding bid” for the dual-fuel ferries on quality and cost grounds, demonstrating the firm “completely understood” what was expected.

Labour MSP Colin Smyth asked if CMAL was to blame for significant design changes.

Mr Anderson replied: “There have been no significant changes in design. That’s quite clear. So what you’re reading is untrue.”

Pressed on the cause of the delays and cost overruns, Mr Anderson said: “That’s one you would really have to ask Ferguson’s. We have a clear contract.

“If any project which had a timescale of 31 months and 33 months is now being extended to 44 months and 52 months, of course there’s going to be cost overruns. It’s quite clear that if a project takes almost twice as it was envisaged, there will be cost overruns."

Asked if any cost overruns were related to design, Mr Anderson said: “None whatsoever.”

CalMac managing director Robbie Drummond told MSPs it would have made a "significant difference" to services if the new ships had been delivered on time.

He said: “We're as disappointed as our communities are that that has been delayed."

Tory MSP Jamie Greene said: “The SNP knew about problems and cost overruns on the yet to be delivered two new CalMac ferries over 15 months ago but chose to say nothing to Parliament, instead a secret backdoor loan was given to the manufacturer.

“It’s nothing short of a complete farce.”

Ferguson Marine was asked for its reaction to Mr Hobbs and Mr Anderson's comments.