The seven Coalition MPs sought to leave the chamber during a one-minute division, which is when the bells are rung ahead of a vote in parliament.
The doors are locked at the end of the bells ringing, which locks members who haven’t made it to the floor of parliament out, but also means MPs can’t leave mid-vote.
Several MPs continued to make their way out of the chamber after Speaker of the House Milton Dick directed staff to lock the doors.
The rush to exit the chamber resulted in a minor injury to a staffer.
Mr Birrell was one of the MPs rushing to leave, but left through a door on the other side of the chamber from where the injury occurred.
Mr Dick issued a blistering statement to the house on Wednesday morning.
“For a staff member of this place to be treated in this way, when they are simply doing their job, is disrespectful and a very serious matter,” he said.
Mr Birrell apologised to the staffer and also to the Speaker.
“Today, along with other MPs, I apologised unreservedly to the Speaker and the house,” Mr Birrell said on Wednesday.
“The cut-off for leaving the chamber is the order of the Speaker and not when the door is physically closed. Lesson learnt.
“I was not aware of the injury to an attendant as I left through a different door. I made no contact with any parliamentary staff member.”
Mr Birrell’s colleagues Angus Taylor, Dan Tehan, Andrew Hastie, Ted O’Brien, Llew O’Brien and Zoe McKenzie also offered their apologies.
Mr Dick said Australians expected their elected representatives to maintain the highest standards of conduct and behaviour.
He understood MPs had busy schedules, but no-one was too busy to ensure the safety of staff.
“I’m committed to ensuring that this building and this chamber is a safe and respectful place of work for all,” he said.
— With AAP
