Union leaders have challenged the Scottish Government to share the legal opinion that prompted it to walk away from supporting BiFab.
The GMB and Unite unions claimed the potential collapse of the state-owned renewables firm was in the public interest and therefore justified the release of legal advice.
Legal advice given to the ministers has not been forthcoming, but a government spokesperson laid the blame at majority shareholder, Canadian-based firm JV Driver.
They added there was nothing they could do, due to “state aid” legislation.
GMB Scotland secretary Gary Smith and Unite’s Scottish Secretary Pat Rafferty have written to Economy Secretary Fiona Hyslop, urging her to lift the “veil of secrecy” surrounding the circumstance of the decision.
The move follows an urgent summit with the minister over the future of the stricken Fife company, which has yards in Methil and Burntisland.
The Scottish Government last week withdrew financial guarantees to support the manufacture of eight turbine jackets for the Neart na Gaiothe (NnG) offshore wind project, resulting in BiFab withdrawing from the contract.
The unions said it was neither acceptable nor credible for the minister not to share the details of the advice that led to the government walking away.
In a joint statement, Mr Smith and Mr Rafferty said: “The First Minister said she would leave no stone unturned to save these yards but if we are to do that then we need to know the full facts behind her cabinet secretary’s decision to remove the financial guarantees for this lifeline contract and time is off the essence.
“BiFab is on the brink but the battle to save these yards goes on.”
A Scottish Government spokesperson said: “The situation at Bifab is a culmination of a number of issues, the main one being the unwillingness of the parent company and majority shareholder JV Driver to provide working capital, investment or guarantees for the company. That is putting the Scottish Government in a position that no other minority shareholder could take on in terms of risk and this is risk to the tax-payer.
“The Economy Secretary held a virtual meeting with BiFab’s majority stakeholder JV Driver and the STUC, GMB and Unite on Thursday to discuss the current challenges facing the company.
“This follows virtual meetings the Economy Secretary held with unions last week, and MSPs, MPs and councillors who have an interest in BiFab’s yards in Fife and the Isle of Lewis earlier this week, to provide an update on the current position.
“We have explored every option and regrettably we remain unable to financially support BiFab. It’s not that Scottish Government does not want to continue to support BiFab, but that State Aid legislation means that is not legally possible.
“We have asked the UK Government for an urgent meeting to explore what support that they may be able to provide to BiFab in recognition that they do not face the same legal restrictions as the Scottish Government.
“We will continue to do everything possible to support the business while recognising the need for us to remain in line with State Aid regulations. In doing so, we remain in regular dialogue with the majority shareholder and the trades unions.”