Councillors have voiced their frustration after delays in work to revamp Toft Pier led to increased costs of over half a million pounds.
Elected members were told of “unforeseen and uncontrollable” delays during the development programme.
Contractor Teignmouth Marine Services was due to start the works on the project in the early part of summer last year.
But the work was held back for two months to allow for necessary consents and licences to be obtained.
That made the project susceptible to weather-related hold-ups, and progress on the piling works was severely affected.
Work on the pier was expected to cost £2.9 million, with £1 million in grant funding coming from The European Maritime and Fisheries Fund.
Unforeseen ground conditions also affected progress on the piling, which contributed to costs rising by £525,000.
Work stopped for in time for Christmas last year, but have been further held back this year as a result of the coronavirus crisis.
Further progress has since been made, and members have been told “substantial completion” will be achieved by November.
Shetland Central councillor Davy Sandison raised questions over where responsibility would lie for the hold-ups. He said a “forensic look” at exactly where the responsibility lay.
Lerwick member Amanda Hawick said it was unacceptable that delays were down to weather.
Fellow town member Stephen Leask questioned whether it would be “the end of the situation” if the extra half million was not paid.
“If we don’t proceed and pay the extra £525,000 and it just goes to a stand still, would that be the end of the situation?”
Head of infrastructure John Smith insisted: “It would be worse than that – we’d have to give the EMFF back their money.”
The issue is due to be raised at the council’s policy and resources committee as well as the full council.