Protesters and MPs who sign them in to Parliament House face a loss of privileges, after unruly pharmacists disrupted Question Time.
Dozens of Pharmacy Guild members took to the parliament's public gallery on Monday, where they began jeering at federal politicians and heckling the prime minister.
House Speaker Milton Dick issued a warning early in Question Time, but the coat-clad pharmacists again disrupted proceedings as they left the gallery.
They continued their loud and disruptive behaviour as they exited the building.
Mr Dick called their behaviour serious and concerning and warned MPs their ability to sign in guests could be revoked.
"It is unacceptable for people to enter the public galleries in an attempt to protest or express their views or disrupt proceedings," he told parliament on Tuesday.
"If you invite a guest into the gallery, I consider their conduct to be a reflection on you. I want to be clear, if this behaviour continues, that privilege may be revoked."
Mr Dick said visitors in the public galleries were "observers, not participants".
"This is the final warning. There will be no tolerance for any attempts to disrupt or interfere with proceedings of the house again."
He said the raucous behaviour posed a risk to parliamentary staff, visitors and politicians.
"It is up to each and every one of us in this house to uphold the highest standards expected of this parliament, which is the heart of this democracy," he said.
The pharmacists were protesting against the government's cheaper prescriptions plan which allows consumers with chronic conditions to collect two months' worth of medicines for the price of one.
In November, a fossil fuel protester glued her hand to an artwork inside Parliament House and was banned from returning for 12 months.
A year earlier, Extinction Rebellion members spray-painted "climate duty of care" on the outer walls of the building.