The highly anticipated trial of a woman accused of murdering three members of her family by serving them a death cap mushroom-laced beef Wellington is due to begin tomorrow.

Alleged mushroom cook Erin Patterson, 50, will be tried in her own community, at the La Trobe Valley courthouse in the mining town of Morwell, in regional Victoria, about 150km south-east of Melbourne.

The courthouse is about a 45-minute drive from her Leongatha home, where police allege she poisoned her family with a lunch on July 29, 2023.

Erin Patterson will have her case heard in Morwell. (Nine)

The mother is facing three counts of murder and one of attempted murder.

She is accused of murdering her mother-in-law Gail Patterson, father-in-law Don Patterson and Gail’s sister Heather Wilkinson.

She is accused of the attempted murder of Heather’s husband Ian Wilkinson.

Don and Gail Patterson.
Don and Gail Patterson. (Supplied)
Heather and Ian Wilkinson.
Heather and Ian Wilkinson. (Supplied)

Erin Patterson has pleaded not guilty to all charges and maintains she is innocent.

Her trial is expected to run for five to six weeks.

A jury of 12 people will be empanelled tomorrow before proceedings will begin on Wednesday.

Erin Patterson
Erin Patterson. (Jason South)

Only six rooms in the courtroom will be reserved for the media despite the case attracting worldwide media attention.

A daily ballot will decide which journalists get to sit in the courtroom.