SCILLONIANS warned MPs this week that the transport links with the mainland were "extremely vulnerable".
Members of the House of Commons transport committee were told by Theo Leijser, chief executive of the council of the Isles of Scilly, that transport was a "serious concern for all residents and businesses".
He said: "The resilience of the transport system as a whole is a key issue and needs to be resolved, providing a dependable and resilient transport solution.
"With the demise of the helicopter, we lost a mode of transport.
"The helicopter provided one mode, there was the sea link and there was a fixed wing mode of transport.
"If you lose one mode of transport – particularly in the winter period when the sea link is not viable – you have one mode of transport left. That makes the transport solution extremely vulnerable."
Mr Leijser was speaking against a backdrop which has seen visitor numbers fall by 27 per cent in the 18 months since the helicopter service from Penzance went out of business. Meanwhile, the cost of air travel has risen by between 19 and 33 per cent above the rate of inflation since 2002. The rises vary by route and which inflation index is used.
However the cost of travel by sea has stayed broadly the same since 2002 or dropped, if using the RPI index.
Robert Francis, a hotelier and director of the Islands Tourism Partnership, said the helicopter to Penzance had been "a lifeline service" as it could fly in low visibility and could often operate when planes could not.
"The islands at the moment are on an economic precipice," he said.
"Our visitors are not going to visit the islands if they don't know when they can get there and when they can get away.
"This big drop in visitor numbers reveals the extent of that problem."
Marian Bennett, co-ordinator for the campaign group Friends of Isles of Scilly Transport, highlighted the extra cost of living on Scilly.
"Food is 20 per cent difference, fuel 25 per cent and bottled gas 41 per cent," she said.
More Scilly news on page 25.