The two CalMac ferries being built at Ferguson Marine shipyard in Port Glasgow are “obsolete” and will spew out “poisonous gases”, according to the former owner of the site.

Jim McColl took aim at the Scottish Government over its handling of the ferries fiasco during an evidence session of the Public Audit Committee at Holyrood.

McColl and the Scottish National Party administration have clashed since an Audit Scotland report published earlier this year revealing that two new vessels built at the yard will now cost around £250m – more than double their original price – and be around four years late.

Both sides have blamed one another, with McColl saying contracts were given “for political purposes”, while First Minister Nicola Sturgeon and her ministers refuting suggestions that there was a rush to get things ready for a party conference at the time.

He told MSPs that they are “not green vehicles”, adding: “They shouldn’t have LNG (liquefied natural gas) vessels there, CalMac didn’t want them, Luke van Beek [a former adviser to the Scottish Government on shipbuilding] gave evidence about speaking to the chief executive at the time of CalMac.

Want to see more SNP fails? – Education Matters