Former finance secretary Derek Mackay is to return to Holyrood to face questions from MSPs on the delays to two CalMac ferries.
He was transport minister when the contract was approved to build two ferries at the Ferguson Marine shipyard in Port Glasgow.
The Public Audit Committee will question him on Thursday about issues surrounding the contract for the ferries.
After it was awarded in 2015, the construction was plagued with delays and the shipyard had to be nationalised.
The two vessels, the Glen Sannox and the as-yet-unnamed Hull 802, were originally due to be completed in 2018, but have since been delayed until at least 2023 and costs have more than doubled from the original price tag of £97m.
Scottish Conservative transport spokesman Graham Simpson welcomed Mackay giving evidence, but insisted a full public inquiry was needed to find out what had happened.
Simpson said: “The Ferguson Marine fiasco has already cost the public purse a quarter of a billion pounds with no ferries yet to show for it – and frustrated taxpayers and island residents are sick to death of the SNP passing the buck.
“Throughout this entire scandal, the SNP’s favourite strategy has been to try and pin all the blame on former MSP Derek Mackay, despite emails from their own civil servants telling a different story.
“So it’s welcome that the former transport minister will now face parliamentary scrutiny, to hopefully shed some more light on this murky saga.”
Liberal Democrat MSP Willie Rennie said: “Every SNP minister, past and present, has been avoiding the question of why warnings about the ferry deal were ignored.
“To date, these errors have has cost islanders and taxpayers five years and £250m.
“I hope that Derek Mackay will use his return to parliament to shed some light on who is to blame for the time and money that has been lost – maybe then ministers will finally do the honourable thing and promise to quit if there are more cost and time overruns.”
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