The Scottish Government is set to receive a legal challenge to their plans for a vaccine passport from a group representing nightclubs.
People will need to prove that they have had two jabs of the vaccine in order to enter large events or particular venues from October.
The First Minister, Nicola Sturgeon, had stated that vaccine passports would help curb the transmission of Covid-19 and keep businesses such as clubs open.
However the Night Time Industries Association Scotland (NTIA) have said they believe there are holes in the government's plans.
They have advised their lawyers to start legal proceedings against the government as a result.
The group is seeking a court order to halt the launch of the vaccine passports until their legal case can be heard, the BBC has revealed.
Those over the age of 18 will require a vaccine certificate in order to be granted admission to a nightclub, an unseated indoor event with more than 500 people, an unseated outdoor event with more than 4,000 people, or any event with more than 10,000 people in attendance from October.
The SNP-Green government drew up a definition of a nightclub in order to give clarity to those in the hospitality industry. It has been described as a venue that is open between midnight and 05:00am, serves alcohol, and which has a designated area for dancing and provides live or recorded music for this purpose.
Sturgeon called for "common sense" to be used by venues over the scheme, she said: "A pragmatic approach will be encouraged, so that businesses can make sensible judgements."
But those representing businesses within the industry have been vocal about their concerns and that the definition may also relate to a variety of other hospitality venues, including bars, pubs and hotel function rooms.
The Scottish Chambers of Commerce said "the practical application of what is being asked is not workable in the timelines being proposed".
Aberdeen nightclub owner Gavin Stevenson - a spokesman for the NTIA - told BBC Radio Scotland that the definition "includes about 2,000 pubs and bars across Scotland in addition to the 100 nightclubs that are actual nightclubs".
The NTIA said that they would launch a legal challenge to oppose the scheme on Wednesday morning.
A statement from the group said "deep-rooted" issues with the vaccine passports could have been avoided if the government had asked for advice from within the industry sooner.
And it said the scheme as proposed was "neither proportionate, nor represents the lowest level of intervention possible to achieve the public health imperative, and it is therefore likely to be unlawful".
It is understood that more detailed guidance for how the scheme will work in reality is to be published by the government in due course.
On Tuesday, Ms Sturgeon told MSPs that ministers were "working closely with business on the definitions that will apply, in order that we hear its concerns and can address them as far as possible".
The First Minister also said the scheme was "a reasonable thing to do".
She said: "We think that their introduction is a proportionate measure ahead of the winter period to try to help us to get transmission down and keep it down, to drive up even further the already high vaccination uptake rates, and to do all that while keeping businesses such as nightclubs and large events open for business rather than having them face again this winter the risk of closure that they faced last winter."
Opposition parties at Holyrood voted against the vaccine passport scheme, but saw it passed by MSPs from the SNP-Green administration.
Scottish Lib Dem leader Alex Cole-Hamilton said it was "no wonder the night time industry is in uproar", adding: "Hopefully this legal action will turn out to be last orders for this illiberal Covid ID card scheme."
