The ban was first introduced on services in November 2020 during the height of the Covid pandemic, with health references linked to the pandemic specifically used in advertising that described the move as a “temporary measure”.
Under the rules, drinking alcohol is prohibited at all Scottish stations and on board ScotRail trains. Visible alcohol, whether opened or unopened, is also forbidden.
A review of the policy was first confirmed almost three months ago.
Stephen Elliot, ScotRail security and crime manager, said: “The alcohol restrictions on ScotRail services were introduced to help us deliver a safe environment for people to travel by train and this remains the case.
"There is no timeframe to change the policy, but we will keep it under review.”
Scottish Labour transport spokesperson Neil Bibby said: “This ban is starting to stretch the definition of temporary.
“It is important to acknowledge that there are real concerns, on the part of staff and fellow passengers, about a small anti-social minority. That anti-social behaviour needs to be tackled. However, it should not be allowed to completely prevent the vast majority of responsible passengers having a drink on the train if they wish to do so.
“This ban risks being a sledgehammer to crack a nut.
“ScotRail should be straight with people about their plans and carry out a full consultation with passengers and staff on this policy."
Advertising featuring on trains as recently as last month to promote the policy stated: “Everyone wants to be able to travel in a safe environment, particularly during Covid-19.
"People who are extremely drunk, or acting in a disorderly manner, have been known to show disregard towards Covid-19 precautions, such as wearing a mask and keeping a social distance from others.”
ScotRail services have been plagued by a rise in anti-social behaviour on services this year. BTP last month predicted an upsurge would be fuelled by warmer weather and busier trains, after new figures showed an 8 per cent increase in violent crime on Scotland’s railways compared to pre-Covid levels.
The alcohol ban was originally introduced with the agreement of the Scottish Government, British Transport Police (BTP) and trade unions.
A ban on drinking alcohol on ScotRail trains after 9pm had previously been in force since 2012.
However, a Freedom of Information response published earlier this month revealed ScotRail had failed to consult police or behavioural experts over the 24-hour ban.
The response stated: "We do not hold any correspondence with partner agencies in relation to extending the ban."
On the continuation of the 24-hour alcohol ban, Scottish Conservatives transport spokesperson Graham Simpson: "The alcohol ban on trains was brought in for understandable reasons.
"Many passengers have welcomed it in terms of delivering a better environment on board trains.
"However, it is right that it is kept under review."
BTP declined to comment on the alcohol ban.
A Transport Scotland spokesperson said: “The potential reintroduction of alcohol on Scotland’s railway services is currently under review.
“However, the transport minister has been very clear about the need to improve safety on our railways for all passengers. Any consideration of the reintroduction of alcohol on ScotRail trains would need to consider this matter within that broader context of passenger – and staff – safety.”