The First Minister is set to announce this week whether the programme, which requires people to show proof of full vaccination status to enter nightclubs and large indoor or outdoor events, will be extended.
A decision is set to be taken by the cabinet on Tuesday morning, with the potential of a mandatory negative lateral flow test result as an addition to the scheme being considered.
The scheme may also be extended to other settings such as pubs, bars, restaurants, cinemas and theatres.
However, the Scottish Government’s 70-page evidence paper on the scheme was roundly criticised over the weekend with Scottish Conservative leader Douglas Ross saying it is “absolutely wrong” to add any further pressure onto businesses.
He said there is “no evidence to suggest vaccine passports do anything to stop the spread of Covid-19.
“Where’s the evidence that these vaccine passports actually work? [The Scottish government’s] own 70-page document can’t tell us and I think this is absolutely wrong to be putting this added pressure and burden onto businesses at such short notice,” Mr Ross said on BBC Scotland’s Sunday Show.
The evidence paper from the government states that extending the vaccine passport scheme to new settings could have a major impact on revenue and footfall for those businesses that could be added to the scheme, but that this could be offset by including an option - rather than a requirement - for a negative test result.
The paper states: “Options that include proof of negative Covid test results (e.g. lateral flow tests) would offset economic harm to a degree because it would increase the number of potential customers able to access the venues (given that not all people eligible to have double vaccination have done so, for a variety of reasons).
"This would apply to business affected by potential expansion of the scheme, and those that already fall within existing requirements."
However, Mr Ross said the main issue was continued uncertainty for the business community.
He added: “We know from many studies already that businesses are strongly opposed to any extension, and we’ve had no idea apart from the First Minister and Deputy First Minister saying some other hospitality venues may be affected, which ones?
“I’ve asked two weeks running, ‘which businesses should be preparing for the expansion of the vaccine passport scheme?’ and the failed to tell those businesses, therefore they can’t prepare properly.”
Responding to the concerns raised by Mr Ross, a Scottish Government spokesperson said: “As the Deputy First Minister has made clear, the situation around the pandemic is serious so we are being open about all the options available to us that may be required to protect the public.
“No decisions have been made and parliament will be informed if and when any decisions are reached. We continue to liaise closely with stakeholders including the hospitality sector.”
The vaccine passport scheme also came under fierce criticism from civil liberties campaigners on Sunday, with Silkie Carlo, director of the civil liberties campaign group, Big Brother Watch, calling for the scheme to be scrapped.
Her comments come as parts of Europe such as the Netherlands and Austria see civil unrest as rules tighten for unvaccinated people and, in Austria’s case, vaccination is made mandatory.
Ms Carlo said the vaccine passport scheme was lacking in evidence and said there were “massive concerns” about the scheme.
She said: “It seems that it is our freedoms that are being sacrificed time and time again, even when there’s no evidence base.
"We have to realistic about this, unfortunately in times of crisis, governments will have power-grabs and will start to infringe on people’s freedoms even when it might not be justified.
“In Scotland, you have had vaccine passports now for almost two months.
"We signalled massive concerns about this from a rights and equalities point of view but also that the fact is it is supposed to balanced against the public health need and we can see it hasn’t worked.
"So why is it now we’re looking at on Tuesday extending the scheme when there is not a scrap of evidence that this has had any positive impact.”
The government said the passport scheme has “likely contributed to a small rise in vaccinations” in younger Scots, and suggested that expanding the scheme could “increase the usefulness of certification” in reducing transmission.
Such a move would also encourage unvaccinated older people to get vaccinated, as well as potentially leading “to a better understanding of the fact that the pandemic is still with us” and poses a threat, the report said.
Ms Carlo criticised the effectiveness of the scheme, however, and said more attention should be paid to the failures of Scotland’s testing programme and contact tracing system.
She said: "The vaccine pass in Scotland was aimed to do two things, one was to increase vaccination rates in younger people, and the second was to reduce transmission.
"It’s failed. There has been a slight increase in vaccination among younger people but there’s no evidence to suggest that that’s connected to this awful, coercive pass scheme.
“The question people should be asking now is why hasn’t the government got a grip on the situation, what’s happening to the tens of millions of pounds spent on Test and Protect, why has contact tracing failed, why are we in the situation that we are in?
She added: “This should be scrapped. On Tuesday the Scottish Government should be talking about scrapping this system, not extending it.
"We’re entering this punitive environment where it’s about policing and spot checking and locking unvaccinated people up and now mandatory vaccines.
"This is incredibly dangerous territory.”
However, Professor Rowland Kao, an epidemiologist at the University of Edinburgh, said he believed vaccine passports “will contribute positively”.
He said: “What we know is that meeting indoors, particularly in settings with large numbers of people are a risk for onwards transmission.
"Keeping in mind, of course that the civil liberties arguments are important, it is true that meeting in settings like in pubs, bars and restaurants, anywhere where there is gatherings of large numbers of people, increases the amount of close contacts, increases the amount of transmission.
"There is no evidence that they [vaccine passports] are the panacea, now the question is whether they can contribute and again speaking epidemiology, if what you’re doing is reducing the amount of contact of unvaccinated people with others in high risk situations, they will contribute positively.”
He added: "Civil liberties are not an absolute, we allow all sorts of restrictions on our behaviour if they have the ability to harm others.
"We have restrictions on speed and things like seatbelts so it is not an either or, we need to do a balance between what the restrictions are doing to individuals and what the application of the measures do in terms of preventing harm to others and we know that vaccines work.”
Scotland has recorded 2,677 new cases of coronavirus in the past 24 hours but no further deaths, according to the latest data.
It means the death toll under this daily measure – of people who first tested positive for the virus within the previous 28 days – remains at 9,478.
The daily test positivity rate was 9.7 per cent, up from 9.3 per cent the previous day, figures published by the Scottish Government show.
There were 777 people in hospital on Saturday with recently confirmed Covid-19 and 58 in intensive care.
So far, 4,338,322 people have received their first dose of a Covid-19 vaccination, 3,937,949 have received a second dose, and 1,408,565 have received a third dose or booster.
On the death figure, the Scottish Government has noted that Register Officers are generally closed at the weekend which may not reflect the most recent numbers.