Shipyard chief executive David Tydeman told MSPs in a letter on Wednesday that the two ferries, which are five years late, would cost up to £209.6 million to complete compared to the previous estimate of up to £122m.
According to The Scotsman, that would mean a total cost of around £300m, including some £83m previously spent, compared to the original contract of £97m.
A damning report into the fiasco by public spending watchdogs Audit Scotland in March had estimated the final cost would be at least £240m.
Mr Tydeman said the second ferry, known as hull 802, is not now expected to be handed over until the first quarter of 2024 compared to the previously scheduled timescale of between October and December 2023.
It is being built at the Port Glasgow yard for the Skye-Harris-North Uist triangle route.
Mr Tydeman also said in the update to the Scottish Parliament’s net zero, energy and transport committee that there was a “one to two month worst case slippage in final handover” of Glen Sannox, or 801 – the first vessel (for Arran route on the Forth of Clyde).
More here on the Clydeside shipyard.