Unite the union has confirmed that its members at the Lerwick Port Authority are taking part in an industrial action ballot over pay, terms and conditions.
Workers included within the ballot at the main port in the Shetland Islands have already unanimously backed industrial action in a consultative ballot.
Strike action by the workers - who include engineers, electricians, joiners and general operatives - is likely to disrupt shipping at the harbour, which will include cruise liners, and oil and gas vessels, as well as general shipping.
