The proposal tabled by a group of coalition deputies plus two deputies of the opposition New Slovenia (NSi), 38 MPs in total, was rejected with eight votes against and six in favour.
Given today's developments, coming after the proposal took heavy flack and was also denied the government's support, the National Assembly will not take a vote on the proposal, meaning uniform packaging will be introduced in 2020.
The proposal also envisaged the setting up of a tobacco fund, which would manage the revenue coming from tobacco excise duties and fund anti-smoking programmes.
Jernej Vrtovec of the NSi said during the debate that while tobacco was absolutely harmful, what was key for the prevention of the use of tobacco products was awareness-raising, and not restriction, especially among youth.
He also said that the question was to what extent the obligatory standardised packaging encroached upon the free business initiative.
Vrtovec's argument was strongly opposed by representatives of civil and health organisations at the session, who supported their opinion with statistics from the countries who had already introduced it and where the number of smokers dropped.
They also pointed to a number of negative consequences on health and, indirectly, to the health insurance fund brought by the use of tobacco products.
There were also warning that the tobacco industry was behind the proposal, as the Commission for Corruption Prevention is currently looking into possible wrongdoings in the lobbying process.
The opposition Left was very critical of the influence of the tobacco industry and had announced it would not support the proposal.
Jani Möderndorfer of the coalition Modern Centre Party (SMC) meanwhile said that he reported every contact with lobbyists, as required by law.
While the MPs who filed the proposal came under fire for directly copying some of the tobacco industry's promotional material when explaining their motion, Möderndorfer is afraid that "if such pressures continue, deputies will stop reporting contacts with lobbyists and there will be less transparency in this field."
The deputies of the coalition Alenka Bratušek Party (SAB) have also contributed their signatures for the proposal, mostly as it envisages a fund aimed at limiting the use of tobacco products.
But its deputy Vojko Starović said that given the arguments that he had heard today, he would not back the proposal.
Robert Pavšič of the senior coalition Marjan Šarec List (LMŠ) was critical of the efforts in prevention, arguing that little has been done in that field.
Dejan Kaloh of the opposition Democrats (SDS) pointed to the decision of the Constitutional Court saying that the freedom of expression, which included advertising, could be restricted if the goals was to protect human health.
As the proposal was voted down at the committee level, it means that it is ending the parliamentary procedure and will not be implemented.
The support for the proposal has also been denied by the government, which recently said it would undermine Slovenia's system of tobacco control, which is very modern and effective.
The government upheld the view of the health and finance ministries, which argued that the proposed changes would undermine the effects of the entire set of measures that is already showing positive results, especially among the young.