Luay Sako last year admitted the murder of his former co-worker, 23-year-old Ms Manno, at her home in Mernda, Melbourne's northeast, in November 2020.
He allegedly stalked Ms Manno for a year before he stabbed her to death.
Sako's defence team had been preparing for a three-day hearing in the Supreme Court in Melbourne next week, where Justice Jane Dixon will hear arguments about how long he should be jailed for.
However, Sako has withdrawn legal instructions from Victoria Legal Aid barrister Tim Marsh and his legal team, Justice Dixon told a brief hearing on Monday.
"Do you want to represent yourself?" she asked him.
"Yes that's correct, Your Honour," he replied, over video link from prison.
Ms Manno's heartbroken family and friends are expected to spend hours reading statements to the court next week about how the murder impacted them.Â
Sako said he wanted to represent himself because he believed he'd been "undermined" and took issue with forensic evidence on the number of stab wounds.
Prosecutors will argue Sako inflicted up to 23 stab wounds, but he disputes this.
"I know and believe I only inflicted two wounds, and that the 21 other wounds were a result of glass-inflicted injuries," Sako told the court on Monday.
Mr Marsh offered to help deliver court documents to Sako in prison, for him to prepare for the hearing, before he flagged concern over his former client self-representing.
"This is a very serious matter and the range of sentences that could be imposed for this matter are amongst the highest that the court could be contemplating," he said.
"I, and the rest of Mr Sako's previous legal team, retain great concerns about whether or not those issues can be properly articulated by Mr Sako."
Justice Dixon said she hoped Sako would reconsider his decision, noting Ms Marsh and his legal team were "wise legal practitioners with a great deal of expertise in the criminal justice system".
Sako will return to court for the plea hearing on January 29.
1800 RESPECT (1800 737 732)
National Sexual Abuse and Redress Support Service 1800 211 028
