The front gates of the Dail were blocked with a cement mixer truck as members returned after their lengthy summer recess.
The words "Toxic Bank Anglo" were written in red letters along the barrel of the truck, which nudged the guarded gates of the Dail at Leinster House on Kildare Street, Dublin, at 7.15am on Wednesday.
A 41-year-old man was arrested at the scene and is being detained at Pearse Street garda station. No one was injured in the incident. A garda spokesman said the suspect is being held under section 4 of the Criminal Justice Act 1984 and can be held for 24 hours.
Onlookers said all the windows on the cement truck were covered in metal grids and had been smashed, with the doors of the cabin welded shut. It appeared some electric cables were cut before the driver escaped through a hatch on the roof.
The registration plate on the cement mixer spelt out the word "bankrupt".
A spokesman for the Dail confirmed the truck was towed from outside the Kildare Street gates of Leinster House at around 9.30am.
"Access arrangements are now back to normal and there will be no disruption to the proceedings or workings of the Houses Oireachtas today," he added.
Fine Gael TD Fergus O'Dowd revealed that at least one garda on duty at the gates of the Dail had to jump out of the way of the truck.
"If it had been later in the morning, staff could have been killed, public could have been killed," said the opposition politician, who was first at the scene.
A garda spokesman later confirmed the 41-year-old man was charged over the incident outside Leinster House and will appear before Dublin District Court, in the Criminal Courts of Justice, on Thursday morning.