King Islanders are being left to "suck up" huge freight cost increases, Mayor Julie Arnold says.
Cr Arnold said changes to island shipping services meant there would be steep increases for goods being sent from or to Victoria.
That is now being done via Devonport rather than by direct shipping between King Island and the mainland state.
Cr Arnold wrote to then-premier Peter Gutwein about islanders' concerns in March, and to new Premier Jeremy Rockliff and the other Braddon MPs on April 19, but was yet to hear anything back except an acknowledgement of receipt from Education Minister Roger Jaensch's office.
"Basically, it's just 'suck it up, King Island,' " she said.
Cr Arnold's letter asked for all freight cost increases to be foregone for three months "to allow proper investigation of the impact on island businesses and residents and genuine consideration of other options".
"We're trying to work out what else can be done," she said on Tuesday.
"Are there other shippers we can deal with?
"What can we do?
"I think we should be allowed three months to do that."
Deputy Premier Michael Ferguson said: "Bass Island Line's new King Island service was established earlier this year with a route between Grassy and Devonport, where TasPorts has established a $2.4 million roll-on, roll-off facility."
"The Devonport port call was a clear preference of the Island community including the King Island Shipping Group, rather than the previous service into Bell Bay.
"I am pleased that Bass Island Line has been able to achieve a reduction in freight rates between King Island and Devonport.
"Under the new arrangements, SeaRoad Shipping is undertaking trans-shipping services for cargo between Devonport and Port of Melbourne.
"Some cargo trans-shipped to and from Melbourne will see a price increase.
"This is as a result of the termination of the direct King Island service to Melbourne due to low and unsustainable usage rates, an important factor in Bass island Line's net loss of $4.4 million last financial year."
Mr Ferguson said Bass Island Line was working with customers experiencing supply chain challenges to support them in sourcing the most efficient solutions.
" ... the government will continue to engage with both BIL and the community through this period of change," he said.
"It is expected that many customers may source more commodities from Tasmania to avoid the trans-shipping task and capitalise on the cheaper Tasmanian service leg.
"This will be a significant opportunity for Tasmanian suppliers and I expect them to be very price-competitive across a range of goods and commodities."
Cr Arnold said "state monopoly" TasPorts had suggested savings on the King Island-Devonport leg under the new arrangements would offset increases in Victorian freight costs.
She said that was naive.
Cr Arnold said there appeared to be a belief Tasmanian supply chains could replace Victorian ones.
She said that was not correct as numerous supplies were not available from Tasmania, including explosives for intending tungsten miner Group 6 Metals, additives and supplies for several island shipping group members and high analysis fertiliser.
Cost implications included:
"The main impost on residents is going be groceries etc.," she said.
"It means supermarket costs will have to go up again."
She said the island's supermarkets were already having to compete with Woolworths shipping goods to the island and she believed some locals were buying groceries on Amazon.
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