Sea trials for a much-delayed and over-budget ferry have been held up due to last-minute changes.

The Glen Sannox – the first of two ferries being built at the troubled government-owned shipyard Ferguson Marine – was due to be in service by the spring, according to a letter from the yard’s chief executive at the end of June.

But in a further update this week, David Tydeman said the Maritime and Coastguard Agency had “re-assessed the application of ‘cargo ship’ rules”, meaning internal changes had to be made to the vessel, including modifications to doorways in crew corridors and three additional staircases.

“This will mean that sea trials will move into the first quarter of the new year and the commissioning of LNG (liquified natural gas) systems at Troon (which must be done after dry-docking) will also move to after Christmas,” Tydeman said in a letter to Holyrood’s Net Zero, Energy and Transport Committee on Tuesday.

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