HUMZA Yousaf has rejected an allegation from the former boss of Ferguson Marine that the firm was handed a key ferry contract to generate good press for the SNP at their 2015 party conference.

Jim McColl told the Sunday Times that ministers pushed through the contract without carrying out all of the standard checks so the contract for two new CalMac vessels could be unveiled at the party’s autumn conference.

The ferries, the Glen Sannox and the other vessel – only known as hull 802 – were due to be ready in 2018. But an Audit Scotland report, which set out “a multitude of failings” in their delivery, said they will not now enter service until 2023 at the earliest at a cost of at least £240 million – two-and-a-half times their original price tag.

McColl, a former economic adviser to the Scottish Government, told the paper that the decision to overrule CMAL’s (Caledonian Maritime Assets Ltd) advice “was made by the First Minister along with Derek Mackay”.

He claimed the contracts were given "for political purposes" and "everything was about the optics and timing the announcements for political gain."

But Yousaf told BBC Scotland’s Sunday Show: “I don’t agree with his assessment.”

The Health Secretary also denied his government was trying to throw disgraced former minister Derek Mackay under the bus for the ferry controversy after Nicola Sturgeon cited his involvement while being questioned in Holyrood last week.

The National:

Yousaf said: “The reason why we were trying to secure the yard was to secure hundreds of jobs.”

He continued: “The First Minister was absolutely upfront at First Minister's Questions this week. Nobody is suggesting that there's not issues. Clearly there have been many lessons for us to learn on this and that's why, for example, there has been parliamentary inquiries. There will be, of course, a review of the actions undertaken.

“Nobody is suggesting for a minute that there aren’t serious questions to ask and the First Minister has said herself that the buck stops with her and as a government we collectively take responsibility.

“Nobody wants to see ferries overrun, both in terms of timescale and in terms of costs. But do not forget if the Government did not take action immediately, that hundreds, hundreds, of jobs would have been lost.”

McColl’s comments have sparked calls from the Scottish Tories for Sturgeon to appear in front of MSPs on Tuesday to respond.

Asked if she should make an urgent statement, Yousaf said: “I’ve never once seen the First Minister shy away from the Parliament. She of course took a significant number of questions on Thursday. And so what Parliament chooses to do is a matter for Parliament. The First Minister has never ducked Parliament whenever she's been asked to appear but we have a minister for transport of course, and any ministers that have been asked to co-operate, with the parliamentary inquiry for example, the Government co-operated fully.”

Pressed on the decision at First Minister’s Questions, Sturgeon suggested that Mackay, who resigned from the Government after it emerged he sent inappropriate social media messages to a schoolboy, signed off on the deal – but insisted as head of the Scottish Government she was ultimately responsible.

However, the Scottish Sun reported over the weekend that it was in fact Keith Brown who put pen to paper on the ferries deal. Brown, currently SNP depute leader and Justice Secretary, was serving as secretary for infrastructure, investment and cities at the time.

“It's not about landing the blame on Derek Mackay,” Yousaf told the BBC. “The First Minister was very clear. It was a matter of public record that while Derek was transport minister the Government took a collective decision. We stand by collective responsibility.”

Yousaf accepted that Mackay did not personally sign off on the contract.

He continued: “The role of minister of transport was a junior ministerial role, Derek of course reported to the Cabinet secretary as junior ministers do. But that is not to say just because Derek Mackay was transport minister – he of course led on that issue at that particular time – but all government was involved. We take collective decisions and nobody is shying away from that.

“I’ll tell you straight here this is not about blaming one individual who’s no longer in government. The Government stands up to its responsibility. Understandably people have questions and of course we are here to answer those questions.”