Inhabitants of the Shetland island of Whalsay are furious about a council decision to research the viability of a tunnel linking it to the Shetland mainland.

The reason for the anger is the delay it will cause to plans to build a new ferry terminal, while the five mile tunnel is discussed.

Following an extended consultation period, a large majority repeatedly came down in favour of building the new ferry terminal, however on 2 February when councillors were invited to back the findings of the consultation, they voted by 13 to five in favour of researching the tunnel. Six months will be spent assessing the viability of the tunnel, which is estimated to more than £110M (US$173.4M).

Whalsay community council wrote to every member of Shetland Islands Council expressing its disappointment at the decision.

In the letter the council wrote that it has been “inundated with phone calls, emails and letters from very aggrieved members of the public” and that the consultation exercise was “farcical”. The letter also says that islanders were told the consultation period was over and that tunnels were not on the agenda.

“The outrage, unhappiness and sense of betrayal felt when the outcome of the meeting was heard cannot be underestimated,“ said the council in the letter.