ISLES MSP Tavish Scott and the chairman of Shetland Islands Council's (SIC) transport committee has called for the proposed Sumburgh Airport car parking charge to be scrapped.
Their demand comes after operator Highlands and Islands Airports Ltd (HIAL) released annual figures that revealed Sumburgh has had the biggest growth in passenger numbers of any of the company's 11 airports.
Scott and SIC transport man Ryan Thomson also accused HIAL of looking to use the well-performing Sumburgh to subsidise its other airports.
A spokesman for HIAL said on Monday that its position remains the same and that it is continuing its plans to introduce the £3 a day parking fee at Sumburgh.
HIAL announced earlier this year plans to introduce the charge at its Sumburgh, Kirkwall and Stornoway airports from 1 July.
While the fee was implemented on time at the latter two airports, the levy has not yet been introduced in Shetland as the work was re-routed through the planning process following discussions with the council.
However, after the news that Sumburgh enjoyed 63,781 more passengers in the 2017/18 than the previous year, Scott and Thomson said the charge should be called off.
"Sumburgh's strength only serves to highlight weaknesses elsewhere," they said in a joint statement.
"As passenger numbers rise in Shetland they fall elsewhere. As we know from HIAL's own figures, Sumburgh Airport makes an operating profit. It is the only airport across the HIAL network, including Dundee and Inverness, to make a profit.
"So why should Shetlanders subsidise Dundee and Inverness Airports by paying to park at our lifeline airport that is 25 miles from Lerwick without any dedicated public transport alternative?"
The pair added that they want to see Scottish islands minister Paul Wheelhouse, who is in Shetland today (Monday) at an oil and gas event, to accept their "argument and tell HIAL to drop these unfair and unwarranted proposals."
Shetland Islands Council had previously called on HIAL to carry out an impact assessment before any charge was imposed.
The government-owned company had been criticised for announcing its car parking charge plans without any prior consultation.
A Scottish Government spokesman said: "We recognise that HIAL’s extension of car parking charges is necessary in order to fund the maintenance and improvement of facilities at their airports.
"While the financial situation dictates that car parking charges must be extended, HIAL has undertaken extensive consultation with stakeholders around the implementation of those charges.
"HIAL is non-profit making and the revenue raised from the parking charges will be directly reinvested in the airports. The Scottish Government provides significant subsidy to HIAL to support its activities which, in 2017-18, totalled over £26 million. This needs to be balanced, however, with a fair level of charges to customers – including airlines, passengers, and tenants – for the use of those services."