A CAMPAIGN group battling to prove the innocence of a North-East mother jailed for the murder of her two children are lobbying politicians in the region to join the fight.

The Portia Campaign believes new evidence from Canada throws serious doubt over the legitimacy of the conviction of Maxine Robinson, from County Durham, in 1995.

Robinson is serving a life sentence in Durham Prison after being found guilty of killing 19-month-old Christine and five-month-old Anthony at the family home in Ouston, near Chester-le-Street, in 1993.

She has always maintained her innocence. Other mothers found guilty of killing infant children, including Sally Clark, whose appeal was dismissed earlier this month, also have doubts hanging over their convictions, according to Portia.

Brian Lowry, a professor of medical genetics at the University of Calgary, believes there is a rare genetic defect which can cause multiple cot deaths in individual families.

He said: "There was a case in the US where a mother was convicted of murder based on a cot death.

"She was pregnant when she went to prison and gave birth there. The baby was removed and placed in foster care. This baby subsequently died under similar circumstances to the first."

Prof Lowry's research claims there is a rare metabolic error in certain parents with a 25 per cent risk of being passed on to offspring.

The Portia Campaign has argued that juries made up of laymen leave the courts open to unsafe convictions in complex medical cases. It is calling for people with understanding of medical issues to make the decisions in important cases.