THE five-years-late fiasco ferries at Ferguson Marine are in 'critical' danger of falling yet further behind schedule, the shipyard's outgoing chief has warned.

Turnaround director Tim Hair — in a gloomy final update to MSPs before leaving his £793k-a-year job — has flagged up a series of issues which he says could severely affect the long-awaited delivery of the ships.

Mr Hair told Holyrood's Net Zero, Energy and Transport Committee that 'significant disruption' to workforce attendance this month is 'likely' and could cause further slippage to timescales.

He also declared that pipework installation on Glen Sannox has fallen behind schedule and revealed that a bespoke design feature on sister vessel 'Hull 802' — insisted upon by procurement quango CMAL — is proving problematic.

Mr Hair said: "At the time of writing the Omicron variant is in its early stages but Ferguson has already seen an increase in absence for self-isolation and testing.

"It seems likely that we will experience significant disruption in January and that in turn might result in lost productivity.

"The resulting impact is impossible to quantify or predict at this juncture."

He insists in his report that the delivery schedules for Glen Sannox, of between July 25 and September 25 this year, and for hull 802 of between April 3 and July 3 next year, remains on track.

But Mr Hair concedes that 'areas of note' have been identified as potential obstacles to achieving those target dates.

He said: "The overall rate of pipework installation on 801 [Glen Sannox] has not achieved planned levels.

"Actions are in place to increase resource and recover the shortfall in early 2022, but this is an important area and represents a critical risk to the delivery of 801."

Mr Hair — who is making way for incoming Ferguson chief executive David Tydeman to take the helm of the yard on February 1 — added: "The hull of 802 differs from 801 in that it has an extra feature known as a ducktail.

"This is an additional structure, the full width of the ship and approximately 2.5m long, which is designed to increase the speed of the vessel for a given power output from the engines.

"At their request, we have for some time been in discussion with Scottish Government, Transport Scotland and CMAL regarding the ducktail.

"These discussions have the potential to impact the schedule for delivery of the vessel and if this occurs we will update the Committee accordingly."

Mr Hair told the committee: "Delivery of 801 in the time window described is achievable but remains challenging.

"The planned increase in production activity in January and February is critical to the achievement of this delivery schedule."

He added: "As noted in previous updates, much of the equipment for the ferries has been installed since 2016 and may have deteriorated since then.

"Although surveys, remediation and replacement have taken place under government ownership there is an unquantifiable risk that equipment problems may emerge during commissioning."

Asked by the Telegraph if Ferguson Marine had experienced workforce difficulties due to Covid since Mr Hair's report, a spokeswoman for the yard said: "The shipyard closed on December 23 for Christmas and production resumed on January 5.

"With only a few working days of production underway since the update was submitted to parliament, there is no change to the position described."

Commenting on the 'ducktail' feature on Hull 802, a spokeswoman for Caledonian Maritime Assets Ltd (CMAL) said: "The ducktail makes the ferry more efficient by reducing resistance, which allows it to burn less fuel.

"The ducktail was included in the original FMEL designs for Hull 802. We're not currently aware of any impact its inclusion will have on delivery of the vessel. We are continuing to work closely with Transport Scotland, Scottish Government and Fergusons to manage the delivery of the two vessels."