The warning comes a fortnight before the Scottish Government’s vaccine passports scheme for nightclubs and large events comes into force on October 1, after the move was passed by the Scottish Parliament last week.
The measure will see nightclubs require a QR code of paper documentation proving customer's vaccination status as a condition of entry.
However, concerns over “market distortion” due to the lack of a clear definition of nightclubs were raised by the Scottish Licensed Trade Association (SLTA) at the Covid-19 Recovery committee in Holyrood on Thursday.
The Scottish Government is yet to settle on a legal definition for what constitutes a nightclub.
But Gavin Stevenson of the SLTA said as many as 2,000 venues could be captured by a definition despite around 100 venues self-defining as a nightclub.
Mr Stevenson said venues facing this additional entry requirement would likely face another “shock” to their income and go out of business.
He told MSPs small pubs and bars owe around £60,000 and £80,000 in debt respectively, with larger high street premises owing more than £150,000.
Mr Stevenson said: “These venues will need a clear run without restriction and without any type of government intervention that reduces their turnover or capacity.
"They’ll need a clear run for years to be able to stay afloat and survive and pay down that debt.
“Hence our immense concern that the approach that is being considered here could have a very serious impact on the attendance of people within these premises, in the turnover then that these premises can achieve.
"If I were to say that these businesses by and large are in a precarious financial position, [that] would probably be quite a dramatic understatement.
"They’re really just not in a position to survive having any kind of shock to their income stream and cash flow and the way that this policy is currently being considered, that kind of shock at the moment seems almost inevitable.
“No matter where the line is drawn we will create market distortion and there will be businesses on one side of the line that artificially prosper and businesses on the other side of that line that, in effect, lose a substantial proportion of attendance and turnover. And that it may in fact put them out of business, it would very likely put many out of business."
Mr Stevenson also criticised the health secretary Humza Yousaf’s approach to nightclubs.
Accusing the SNP figure of parroting “misconceptions” about the nightclub sector, the SLTA representative said no evidence showing additional risks caused by nightclubs had been shown to the group.
He said: "I would also note that there are some very common misconceptions that have been repeated by people within Scottish Government, specifically the Cabinet secretary for health on radio a couple of times now. [He] has noted that he thought nightclubs have had poor ventilation or have had challenging circumstances with regards to ventilation.
"I think it would be fair to say that actually large nightclubs probably have some of the best ventilation systems of any premises type in Scotland simply because of the nature of the business.
"They invest heavily in ensuring customer comfort, which involves frankly putting a lot of fresh air through those premises.
"We are not convinced that vaccine passports are a proportionate measure to take at this time and we think for our sector particularly, they come with some unintended consequences that might be virtually impossible to overcome and may in fact be counter productive in terms of achieving Scottish Government’s aims.”
Scottish Professional Football League (SPFL) chief executive Neil Doncaster separately stressed that visual checks of vaccine passports was the only way forward for Scottish football.
He also warned of the “considerable additional cost” involved for clubs as he addressed the Scottish Government's Covid-19 committee ahead of the planned implementation of vaccine certificates for large scale outdoor events attended by more than 10,000 people.
He stressed any technological solution was "untried and untested" and that affected clubs – Rangers, Celtic, Aberdeen, Hearts and Hibs, who each have in excess of 10,000 season ticket holders, as well as the Scottish national side – should be allowed to manage their own approach to vaccine passports given the lack of time to plan.
Mr Doncaster told MSPs: "In terms of stewarding there is a real shortage of security staff and stewards within the market and creating an outer cordon, which is the only realistic way we believe of implementing such a spot checking scheme clearly, will require a great many more stewards.
"I had discussions with a number of the clubs who would be involved and they believe that the costs purely in terms of stewarding and infrastructure will be upwards of £5,000 per game and that is before any technology costs.
"The only certainty is that there will be considerable additional cost and clearly we are in dialogue with Scottish Government officials as to what extent there may be support for those additional costs.”
Mr Doncaster had previously said that the SPFL was "concerned" about the practicalities of delivering the scheme, warning it risked fan "disorder", and that spot-checking was the only way it can be done.
It comes after plans to introduce vaccine certificates in England were scrapped.
UK health secretary Sajid Javid has said they may be forced to revive the unpopular policy of vaccine passports south of the Border if the NHS comes under severe pressure in winter.