Five of Scotland's leading tourism and business groups fear that thousands of self-catering businesses could be wiped out under a planned rates revaluation.
The organisations have teamed up in a collective industry call to the Scottish Government expressing concern over the potential impact of the draft 2026 proposals for non-domestic rates (NDR).
They are the Association of Scotland's Self-Caterers (ASSC), the Scottish Tourism Alliance (STA), Scottish Land and Estates, the Federation of Small Businesses (FSB) and Scottish Agritourism.
The group says businesses could face a rise in payments of between 120 to 300 per cent under the developing proposals.
It comes at a time of already well-documented industry concerns over the sustainability of businesses amid the cost of living crisis and the likely costs of the new visitor levy.
The joint letter of warning from industry leaders is supported by former Scottish Government Minister Fergus Ewing MSP, now an independent representative for the Inverness and Nairn constituency after leaving the SNP.
Mr Ewing called the rates revaluation "the day of the Jackal" for small self-catering businesses.
The joint letter to the Minister for Public Finance Ivan McKee warns the move "poses a serious threat to the viability of thousands of businesses across the country, with immediate repercussions expected for rural and island economies".
It urges him to make an urgent intervention and carry out a review of the emerging valuation approach.
The letter also highlights the severity of the situation reported by operators across the country.
It says early indications suggest many are facing unprecedented draft increases in Rateable Values (RVs), with rises averaging around 120 per cent and some facing rises approaching an "eye-watering" 300 per cent.
It also says many depend on the Small Business Bonus Scheme (SBBS) to remain viable, with inflated draft RVs risk pushing them out of qualification for any rates relief.
It is claimed for those already operating on tight margins, such huge increases would pose a significant and, in some cases, existential risk.
Also highlighted is the important role those kinds of business play in the rural economy, boosting local employment, visitor spend and community sustainability.
It also flags up the increased levels of stress and anxiety faced by operators as they absorb "yet another major regulatory and fiscal shift", with two-thirds of respondents saying the draft valuations have already caused significant stress or deep concern for the future.
The letter's signatories have questioned the reliability of the evidence base informing the revaluation.
Of the 16,513 self-catering units on the valuation roll, only 501 are recorded as rented.
Bed space rates underpinning the new national model were derived from just 135 properties, less than 1 per cent of the sector, and it is claimed were "clearly unrepresentative of the breadth and diversity" of Scotland's self-catering sector.
With an eye ahead to the Scottish Budget next month, the organisations call on the Scottish Government to introduce targeted reliefs, restore SBBS thresholds and ensure that additional support is available during this destabilising period.
They also stress the need for enhanced scrutiny of the valuation methodology to ensure the final outcome is fair, robust and proportionate.
Mr Ewing, who was Scotland's longest serving tourism minister, said: "Unless the Scottish Government intervenes now, these rates valuation notices will directly result in the assassination of thousands of small hard working self-catering businesses.
"It will be 'the day of the Jackal' for wee tourism businesses, executed by the assessor on the tacit orders of the Scottish Government."
ASSC Chief Executive Fiona Campbell MBE said: "The emerging draft valuations represent a sharp financial shock that micro businesses simply cannot absorb.
"These businesses are absolutely vital to the fabric of rural and island Scotland, yet many are telling us they are reaching breaking point.
"Alongside the rising costs and regulatory changes of recent years, the uncertainty created by these draft Rateable Values is piling enormous pressure on both livelihoods and wellbeing.
"If these vital businesses close, the economic and social effects will ripple through communities."