What was billed as a major Convoy to Canberra protest has failed to attract significant numbers.
Protest leaders had touted Tuesday, federal budget day, as the biggest anti-vaccine mandate demonstration since the vast majority of their followers left the capital last month.
ACT Police said two people were arrested for "failing to comply with police directives", including one who refused to undergo a random breath test.
At least one person has been arrested after refusing to comply with police instructions, including declining to undergo a random breath test.
The movement hit a high water mark in February, when roughly 10,000 people - made up of anti-vaccine mandate protesters, COVID-19 conspiracy theorists, and sovereign citizens - descended on Parliament House.
At that time, some protest leaders urged supporters to remain in the capital, arguing the turnout would be impossible to replicate once the majority returned to their home states.
Just 500 were estimated to have turned out in front of Parliament House on Tuesday.
"We are down in numbers, but strong in spirit," leader Christian Marchegiani told the crowd, urging them not to lose optimism.
No arrests were made outside Parliament, where protesters were peaceful.
But traffic was briefly disrupted on Commonwealth Avenue, and ACT Police warned Canberrans further protests in the City and Parliamentary precinct is possible throughout the week.
"Drivers should consider alternative routes if possible," a spokesperson said.
"ACT Policing thanks the Canberra community for their ongoing patience when encountering protestors."
Some protesters have slept for days on the lawns of Parliament but, with only tents considered a camping "structure", those sleeping in swags were not violating the law.
In a shift since the movement's high point, speeches outside Parliament were dominated by politicians running in May's federal election.
United Australia Party leader Craig Kelly and One Nation senator Malcolm Roberts asked for votes while parroting conspiracy theories about COVID-19.
Addressing the poor turnout, Mr Kelly claimed each protester represented a thousand unable to travel to the ACT.
Liberal senator Gerard Rennick, who has no medical training, revived his attacks on COVID-19 vaccines over side effects.
THREAD: The biggest day for the #convoytocanberra - Budget Day - is upon us, and so far it’s a low-energy fizzler 1/
— Finn McHugh (@FinnianMchugh) March 29, 2022
The former was significantly more prominent on Tuesday, with a notable presence of UAP volunteers.
Extremist Riccardo Bosi, whose rhetoric has been laced with threats to law enforcement, did not appear present at the protest by mid afternoon.
Bosi, a former SAS officer, has repeatedly outlined plans for overthrowing the democratically elected government. Despite allusions to executions of journalists, he insists his designs are peaceful.
Roughly 100 protesters have remained in and around the ACT since the movement splintered, holding small but disruptive demonstrations across the capital.