Experts call for botched CalMac ferries to be scrapped or radically redesigned
The call came as it emerged Ferguson Marine's bid for the vessels was the highest of those submitted.
The partially-built Glen Sannox and its unnamed sister ship are now expected to cost twice their original £97 million price and be completed three years late in 2021-22.
Consultant and author Roy Pedersen told the Scottish Parliament's connectivity committee they should both be scrapped and the work started again.
He said: "If it was me making the decision, I would scrap both of them."
Alf Baird, a former professor of maritime business at Edinburgh Napier University, said their design should be stripped down to basic vessels with their unnecessarily large passenger capacity reduced.
He said the design was "specifying what is in effect a mini-cruise vessel to run a utilitarian shuttle ferry which is basically a bus".
Scottish Liberal Democrats transport spokesman and committee member Mike Rumbles said a letter from Scottish Government agency Transport Scotland to infrastructure secretary Keith Brown in 2015 revealed that six shipyards tendered for the contract and Ferguson Marine was the highest-priced bidder.
When he asked why that was, Mr Pedersen told the committee: "I don't know the answer, but three things spring to mind - one is incompetence, the other is vested interest and the other is corruption."
MSPs also queried why the ferries - for the Arran and Skye-Harris-North Uist routes - were designed to run on either diesel or liquefied natural gas (LNG).
They were told LNG would have to come from the south of England - a 1,000-mile trip to the ferry terminal at Uig, in the north of Skye.
Mr Pedersen said: "That in itself is going to be probably on a diesel lorry."
He added that it would "negate the relatively minor advantage" to the environment of using LNG.
The consultant also observed: "Why build a ship with a capacity of 1,000 passengers for a route, namely the Uig routes, on which there has never been more than 312 passengers carried on any sailing?"
The Scottish Government took over the former Ferguson Marine Engineering Limited (FMEL) yard in Port Glasgow last August.
It has said the ferries will now cost an extra £110m to complete.
But it stressed that price had not been the only factor considered by ministers' ferry-owning Caledonian Maritime Assets Limited (Cmal) offshoot in awarding the vessels contract.
A spokesperson said: “As is routine during procurement processes, the decision to award the contract was not based on price alone.
"It was made clear to tenderers the quality/price ratio for assessment of proposals was 50:50 and would be taken together.
"On a combined mark covering both assessment factors, the FMEL tender achieved the highest overall evaluation score.
"After detailed consideration of the quality and costs submissions, the Cmal executive team recommended the award of the contracts to FMEL.
“The Scottish Government is committed to transparency on these issues, and have kept Parliament informed of progress and proactively published information on our website.”
On the call to scrap the vessels, the spokesperson said: “Scottish Ministers considered all options when deciding how to proceed.
"Ministers’ commitment is to the vessels, the workforce and the yard.
"Scrapping the vessels and starting again would not meet those objectives.”