THE First Minister and Deputy First Minister should be asked to give oral evidence to a committee of MSPs investigating the delayed Ferguson Marine ferries, the Scottish Liberal Democrats have said.

The party’s economy spokesperson, Willie Rennie, said that Nicola Sturgeon, John Swinney and former infrastructure secretary Keith Brown should join former transport secretary Derek Mackay in giving evidence at Holyrood’s Public Audit Committee.

Mackay was transport minister when the contract was approved to build two ferries at the Port Glasgow shipyard and has already been invited to give evidence in person after the Scottish Parliament’s summer recess.

Who is asked to give evidence is up to the Public Audit Committee, which currently has former Scottish Labour leader Richard Leonard as its convener. There are no LibDems on the committee or on the list of substitute members.

READ MORE: Island church says 'wrath of God' to blame for ferry cancellations

Following the award of the ferry contract in 2015, the construction of the two CalMac vessels was plagued with delays and the shipyard was 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 £97 million.

Rennie said: “It is only right that Derek Mackay should appear before Parliament but he was not the sole member of Nicola Sturgeon’s cabinet involved in signing off this multi-million-pound contract.

“The public have heard from transport officials and shipyard representatives that John Swinney, Keith Brown and Nicola Sturgeon herself were all involved in the decision to take over Ferguson Marine and to provide it with extensive financial support. They should join Derek Mackay in giving evidence to Parliament.

“Island communities have been sorely let down by the Government and they have waited too long for answers.

“These communities depend on the success of ferry contracts like this one. The SNP, however, have done next to nothing to show that they understand this."

Rennie has written to the convener of the Public Audit Committee, Richard Leonard MSP, asking him to invite Sturgeon, Swinney and Brown to give oral evidence.

Mackay has already provided written evidence to the committee, in which he said there was a “high level of confidence” in the shipyard.

A Scottish Parliament spokesperson said: “Prior to summer recess, the Public Audit Committee agreed to invite the former minister for transport and islands and the former chief executive of Transport Scotland to give evidence in its inquiry.

“Choosing witnesses to give evidence beyond these individuals is a matter for the committee.”

And a Scottish Government spokesman said: “Invites to parliamentary committees are entirely a matter for individual committees – not for the Government.”