THE mother of a nine-month-old baby boy killed by his father with a tomahawk in 1995 has mounted a vitriolic Facebook campaign to try to stop him being released from prison on parole.

Port Lincoln woman Valerie Staunton is urging people to lobby Premier Mike Rann to reject her former partner, Mervyn Keith Hull's, bid for freedom - even though the Parole Board is yet to recommend it.

Ms Staunton's Facebook Cause page has gathered more than 6400 members, and supporters have written and emailed letters to Mr Rann's office, that of Correctional Services Minister Tom Koutsantonis and the Parole Board urging Hull's continued incarceration.

Hull, now 46, pleaded guilty in 1996 to the murder of his son Cameron, on Eyre Peninsula. The Supreme Court was told Hull had attempted to kill both himself and Cameron by carbon monoxide poisoning in his car, but this had failed. He said he then did not want his son to suffer and so struck him in the head and neck with a tomahawk to kill him.

The court was told Hull had an acrimonious relationship with Ms Staunton, and the incident occurred during an access visit while Hull was suffering severe depression. He feared his future access was under threat after not returning Cameron by an arranged deadline.

Hull was sentenced to life in prison with a nine-year non-parole period.

The Full Court extended that to 14 years on appeal. This expired last August and he has now applied for parole.

Ms Staunton yesterday said she felt Hull had not spent enough time in prison and she feared "for my safety and the safety of my children".

"He might be behaving in prison but if you put him back into society he may not handle the pressure, which has been proven in the past," she said.

"He would react and I would be a target because he blamed me for what he did; he did it to hurt me, to punish me.

"Murderers should serve life in prison, he should die and he should rot in prison. He should serve his life sentence and there should be no parole."

Parole Board chairwoman Frances Nelson, QC, yesterday said while the board had considered Hull's case, no recommendation had yet been sent to Executive Council.

She said Hull had not caused any problems while in jail and "appreciated almost immediately the gravity of what he had done". "It is a burden that he also has to carry," she said. Ms Nelson said the campaign against Hull's release was "unusual in its intensity" and she had never witnessed "a campaign of this magnitude".

"I understand she is the mother of a small child who was killed, and I can totally empathise with her loss and grief," she said.

"But her approach to the case is a very subjective one, and that is the reason we have independent judges because they have no emotional involvement and they apply a sentence which is not motivated by subjective feelings.

"I would think the wider community, if they had regard to all of the circumstances, would have a balanced view."

Ms Nelson would not comment when asked about the board's recommendation in this case.