The Scottish Government intervened in the sale of the Dalzell and Clydebridge steelworks from Tata Steel to the conglomerate, Liberty Steel, ultimately owned by steel magnate Sanjeev Gupta.
To facilitate the deal, the Government bought the site for £1 and immediately sold it to Mr Gupta’s company in a ‘back-to-back’ sale.
However, last year, Mr McKee informed MSPs the deal may have broken state aid rules, which could leave the Government with a multi-million pound environmental clean-up bill.
This could happen if current owners, GFG Alliance, collapse, leaving the cost of clean-up to be picked up by the taxpayer rather than the former owners, Tata Steel.
It is this clause that is understood to have potentially broken state aid rules.
Asked by the Scottish Liberal Democrats why it was necessary for the Government to take on full ownership of the site as part of the back-to-back sale, Mr McKee failed to provide clear reasons.
He said: “The three parties to the sale and purchase of the Lanarkshire steelworks on 2016 – Tata Steel, Liberty House and the Scottish Government – were all aligned in agreeing a transaction that secured the earliest realisation of the commercial and wider economic benefits of the deal, and the selected structure was the best available means to deliver this.”
Willie Rennie, economy spokesperson for the Liberal Democrats, said ministers would be “biting my arm off” to say the Government was not on the hook for a significant bill if it was true.
He said: “We have known for some time that the Scottish Government was briefly the legal owners of the Dalzell steel works, but shifty SNP ministers are still unable to give a straight answer about why this was necessary.
“If ministers have promised to protect Tata from the costs of cleaning up the Dalzell site, then taxpayers could be on the hook for tens of millions of pounds.
“If this is not the case, then you would think ministers would be biting my arm off to tell me.
“Fundamentally the problem here is an untrustworthy SNP Government, which prefers to operate in the shadows than tell the truth about the deals they sign with taxpayers’ money.
“Sooner or later these dealings are going to be dragged into the light. The choice for the SNP is whether this process is swift and transparent or slow and painful.
“Ministers should come to Parliament and spell out just what benefits there were to all parties involved from the Scottish Government taking on ownership of the steelworks.”
A Scottish Government spokesperson said: “The Scottish Government acted at pace in 2016 to support a transaction involving Tata Steel and Liberty House to ensure steel communities in Scotland had a future.
“This saved the Dalzell and Clydebridge steel works, rescued more than 100 jobs and retained steel plate production in Scotland.
“Were any future environmental liabilities to exist in respect of the Lanarkshire steel plants, the responsibility and associated costs would lie with the site owner or developer of the land.”