Tarrawingee man Brendan Nugent, 43, remained quiet during his brief appearance in Wangaratta Magistrates Court on Wednesday morning.
It's alleged he intentionally struck Dr Haines with his Toyota LandCruiser outside her electorate office in Wangaratta, northern Victoria, on Monday afternoon.
The 65-year-old federal MP underwent emergency surgery at The Alfred hospital in Melbourne that night but one of her legs could not be saved.
She remains in a critical but stable condition.
Nugent was charged late on Tuesday with dangerous driving causing serious harm, intentionally causing serious harm and causing harm to a Commonwealth public official.
His lawyer Chirag Patel told the court it was the 43-year-old's first time in custody.
Nugent suffered from the neurological condition idiopathic transverse myelitis but otherwise had not been diagnosed with any mental health conditions, Mr Patel said.
The condition is a rare disorder caused by inflammation of the spinal cord.
The lawyer asked for Nugent to be seen by a medical practitioner as he was suffering from concussion.
Nugent did not apply for bail and was remanded in custody to face court again in February.Â
Earlier on Wednesday, Victoria Police Commissioner Mike Bush told reporters he believed the incident was a deliberate but isolated act.
Authorities were not ruling out further serious charges, including one of attempted murder, he added.
There was nothing to suggest Nugent was part of the so-called "sovereign citizen" movement, Mr Bush said, but police were not ruling it out while they trawl the accused's history and online presence.
There was no intelligence to suggest the 43-year-old might carry out the alleged attack, he said.
A joint counter-terrorism task force combining Victorian and federal police, and spy agency ASIO are investigating the incident.
"The shocking alleged attack yesterday is what many had been dreading for some time," Australian Federal Police Commissioner Krissy Barrett said.
"I hope that this terrible event, that will forever change the life of the member for Indi and her family, gives our country time to pause and reflect on the growing threats and unlawful behaviour against those who hold a Commonwealth office.
"The current criminal threat environment is febrile."
Mr Bush said additional security preparations were being made in the lead-up to Victoria's November state election.
ASIO, the Australian Federal Police and Home Affairs Department will also brief MPs and senators on security later in the day.
Those bodies have held six such briefings for politicians in 2026, having warned politicians for years about a surge in violent rhetoric and threats against their physical safety.
20°C