A man who murdered his mother less than two hours after police evicted him from their home, then claimed she was killed during a home invasion, has been jailed for 20 years.

Just before midday on May 24 last year, Jamie Ian Willis complied with a police order that he leave the Werribee home he shared with his mother, Caroline, after a magistrate issued an intervention order against him three days earlier.

But about 1.20pm that day Willis, after using the drug ice, returned to the Taworri Crescent property and stabbed his mother at least 19 times with a kitchen knife as well as bashing her to the head and neck.

Willis stayed in the house overnight but did nothing to assist his 70-year-old mother.

He called triple zero the next day, after she had died.