Council tourism chiefs are planning to pull the plug completely on all funding and support for Tourist Information Centres (TIC).
Offices already stretched to the limit by severe cuts could close if secret draft proposals for a "managed exit" by the authority's tourist arm within six months go ahead.
Workers at Visit Cornwall, the arm's-length company set up to look after tourism, could also lose their jobs under a consultation launched this week by officials.
Axing the £180,000 budget to support the 25 TICs in the Duchy could almost single-handedly wipe out a budget reduction of £200,000.
But critics say cutting TICs adrift and focusing on marketing the county through the Visit Cornwall website will hit "the backbone" of the tourist businesses which make up 70% of the market.
The move would be a body blow to offices like Falmouth, St Ives and Penzance, which closed when funding was removed following the creation of the new unitary authority and were only able to open as private sector operations with help from the council agency.
Tina Evans, a B&B owner and chairman of the Padstow Area Tourism Business Forum, which runs the town's TIC, said the move will have a "huge knock on effect" on small hotels, self-catering and bed and breakfast providers, though the "big boys" will continue to "prosper".
Padstow TIC, which sees more than 80,000 visitors each year, has been privately run since 1992 and "washes its face" with a £2,000 profit.
But only with £10,000 from the town council and help in the form of free access to the main booking system worth £15,000 from Visit Cornwall.
"We would be £13,000 in the red and couldn't operate but how we would find additional funding I am not sure" Mrs Evans added.
"A lot have got involved on the understanding of this support – if we withdraw that people will say why bother if the county tourism body cannot even support us with this (booking) system.
"Digital marketing is such a narrow point of view to put all your eggs in one basket."
Malcolm Bell, head of Visit Cornwall, says the key is to capture the "elusive" first-time customers, who were 80 or 90% likely to return.
Mr Bell did not wish to comment on the specifics of the review as he is due to speak to staff today.
In a statement, Cornwall Council said the future priority would be "in depth customer research, high quality marketing and PR and making the most from modern ICT such as social media".
"VisitCornwall are currently in the process of reviewing their plans for this year in order to ensure they deliver the priorities which were agreed by the scrutiny committee in February, the statement added.
"This process has not yet been concluded."
