A pilates instructor has been jailed for life to serve a minimum of 12 years for the murder of his elderly mother who he strangled after a row over a telephone bill then took his dog for a walk.

Geoffrey Hobbis pleaded guilty at an earlier hearing at Winchester Crown Court to the murder of 79-year-old Barbara Hobbis, who was described as ''vulnerable'', on May 31 this year.

Sentencing him, the judge, Mr Justice Teare, told Hobbis: ''It appears that in the week or so before the dreadful event, your mother's sister had died.

''That had saddened her and she had had difficulty using the mobile telephone when phoning her other sister.

''It seems there was an argument between you and your mother over her unwillingness to use the mobile phone, she preferred the landline, you preferred the mobile phone because it was cheaper.

''There may have been other arguments at this time. What seems to have resulted is the two of you stopped speaking to each other and she may have suggested that you move out.''

Describing the offence, the judge continued: ''It appears that you grossly and wholly unjustifiably over-reacted to these matters by strangling your mother.''

William Mousley QC, prosecuting, told the court that the 58-year-old had lived with his mother for 20 years, and for the past five years at Brooklyn Gardens, Fleet, where he strangled her.

He described how the defendant had been arguing in the previous week with his mother over her preference for using the house telephone rather than a mobile phone that he had bought her which had inclusive minutes.

Mr Mousley said that his mother preferred the larger buttons of the house phone which she found easier to use and that the argument had upset her enough to considering selling the bungalow.

He said: ''This had caused a dispute between them which resulted in them not talking to each other.''

He continued: ''He wanted to save money, this grew into him telling her that she was always belittling him.''

Mr Mousley said that at 10.30am, Hobbis called the home of his brother, Paul, and spoke to his wife, Sally, telling her that he had strangled his mother and asked them to look after his dog.

He added that the defendant then left his home and took his dog for a walk, greeting the postman as he passed him.

His sister-in-law alerted the police and officers arrived at the house and found Mrs Hobbis on the floor on the lounge and carried out CPR.

She was to die later that day in hospital.

As the defendant arrived back at the bungalow with his dog, he was asked by the officers who he was, to which he replied: ''I am the one you are looking for.''

The court was shown footage from body-worn video cameras worn by the officers which showed the defendant ask: ''What will happen to the dog, I do worry about the dog.''

Hobbis told police in interview: ''It just all got on top of me, it was all building up and I lost control really, I flipped and got up and grabbed her round the neck.''

Mr Mousley said that Hobbis had not shown ''no emotional reaction'' when he was arrested and had not asked over the wellbeing of his mother.

Kevin Izod, defending, told the court that Hobbis was normally a ''placid and calm'' man who had been planning to move to India to train to become a yoga teacher.

He said: ''What is sad about this matter is the cause of it is a silly thing, it appears to be an argument over a mobile phone which has escalated.''

Mr Izod added that his client did not have a mental health disorder but was under a period of stress and had been contemplating suicide and had taken an overdose a year previously.