A mother has been jailed for attempted murder after she tried to kill her two sons by poisoning them while they slept.
Lisa Walmsley, 52, lit disposable barbecues in her adult sons' bedrooms in a bid to kill them through carbon monoxide poisoning.
Her plan was thwarted after one escaped and called police.
Walmsley, who had been suffering mental health problems, also planned to kill herself.
Described as otherwise being an 'excellent and loving mother', she was jailed for five years and four months.
Manchester Crown Court was told Walmsley had sought help and medication after experiencing a number of 'challenging' events in her life including the death and ill health of family members.
She separated from her husband in 2010, leaving her to bring up her two sons, one of whom suffered mental health problems of his own.
She had previously researched methods of killing her children after she 'simply decided it would be better if they all died', prosecutor Rob Hall said.
Walmsley and her sons - then aged 19 and 21 - had spent New Year's Day together at their home on in Cheadle Hulme, Greater Manchester.
That evening one of her sons got up after midnight to make some toast, while the other watched a film. Walmsley was 'pacing' in the kitchen.
She then went into their bedrooms and lit the disposable barbecues.
After one of the burners was discovered, Walmsley tried to blame the smoke it had created on burnt toast.
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One son left the house 'in fear' after recalling a 'threat' his mother had made years before - that she would 'gas herself and the children'.
She encouraged the other to drive with her in the family car, where she had lit three further barbecues.
Shortly after she stopped in a car park and said: "Why don't we kill ourselves tonight?".
Hall said the son initially agreed, but what he actually wanted was his mother's help and support for his own problems.
The pair sat in the car until the fires extinguished.
Walmsley then went to a nearby supermarket for a ‘more effective’ burner but the store was closed.
Her son said he wanted to go home, but Walmsley said they couldn't. At 1am, the police arrived at the family home and found her other son. The fire service attended and found high carbon monoxide levels in the house.
Police carried out a 'controlled stop' on Walmsley's car at 4.20am and she was arrested.
"It is fair to say that they have in effect forgiven their mother," Hall said of Walmsley's two sons. But her lawyer Richard Simons said their relationship has been damaged 'irrevocably'.
A doctor concluded that her crimes were a 'direct manifestation of her severe depressive illness' and she perceived their situation to be 'so hopeless and distressing' that she would 'protect them from further suffering'.
She feels 'regret and shame' for her actions and is profoundly contrite and remorseful, the court was told.
Walmsley admitted two counts of attempted murder.
Sentencing, Judge Patrick Field QC told her: "It is a disturbing feature of this case that those attempts to kill your sons were not spontaneous.
"You decided upon carbon monoxide poisoning and you set about planning their deaths.”
The judge reduced Walmsley's sentence taking into account her mental health problems.
Following the hearing, Detective Constable Laura Burgess paid tribute to Walmsley’s sons.
She said: “Since that awful day, these two men have shown immeasurable strength, not only in trying to process what they have been through, but also in helping see justice done.
“Their lives have been changed forever.”
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