Failures at a mental health unit gave a troubled young mother accused of murdering her four-year-old son the "opportunity and time" to commit suicide, an inquest jury ruled today.

Emma Manser, 24, was found with a ligature round her neck in her room at The Dene mental health facility for women in Hassocks, West Sussex, on July 17 last year.

Ms Manser, from Exeter, Devon, was admitted there after being charged with murdering her toddler son, Ryan Manser, and attempting to kill her mother, Wendy Richards, at her home in April 2007.

A three-day inquest heard there was no policy stating specific staffing levels per shift at The Dene, resulting in a shortage of staff on the day Ms Manser killed herself.

Returning a narrative verdict, the inquest jury of five women and three men noted that the "staff shortage resulted in observation care plans not being adhered to".

Jurors were told observations every five minutes in her room were not strictly observed, although they also heard she could have taken her life in two minutes.

The verdict, read at Haywards Heath Magistrates' Court, added: "The cumulative effect resulted in Emma Manser having the opportunity and time to end her life."

Ms Manser died from asphyxia caused by a self-applied ligature and her death was the result of "suicide beyond all reasonable doubt", the inquest heard.

Following the verdict, Ms Manser's father, Robert Manser, said that generally staff at The Dene looked after his daughter's wellbeing.

But he went on: "I have seen in this inquest that on the day Emma died there was a lack of communication in the ward and I'm concerned that the buck has been passed to a trainee in the hearing.

"It looks like the protection of my daughter from herself was not adequate on that day. I think the ward was understaffed. When Emma was well, she was a loving daughter and mum, and a joy to be with."