THE trial of a Suffolk father-of-two accused of murdering his wife came to a dramatic end yesterday when he pleaded guilty to manslaughter.Gareth Lewis had denied murdering his 42-year-old wife Amanda, who was having an affair with his best friend, Nigel Langfield.

THE trial of a Suffolk father-of-two accused of murdering his wife came to a dramatic end yesterday when he pleaded guilty to manslaughter.

Gareth Lewis had denied murdering his 42-year-old wife Amanda, who was having an affair with his best friend, Nigel Langfield.

But he admitted manslaughter by reason of diminished responsibility after psychiatrists for the defence and prosecution agreed that his responsibility at the time of the killing was "substantially" impaired.

Lewis, who killed his wife with a single stab wound to her stomach during a row at their Bury St Edmunds home, is due to be sentenced at Ipswich Crown Court today.

Jurors in the trial, which started on Monday, arrived at court yesterday expecting to hear further evidence called by the prosecution.

However, after reading statements from a policeman and a paramedic who attended the family's home in Fitzgerald Walk after the stabbing, and playing a recording of Lewis's 999 call, the case was adjourned for several hours - allowing the psychiatrists to establish if there was any common ground between them.

When the court reconvened, prosecution counsel Graham Parkins, QC, said the issue between the experts concerned the degree of impairment of responsibility suffered by Lewis.

"Having discussed the case today they agree the impairment of responsibility does meet the test of being substantial," he said.

He said that as both experts were in agreement that a defence of diminished responsibility was open to Lewis the prosecution would not call any further evidence.

The murder charge was then put again to Lewis who replied "not guilty but guilty to manslaughter by reason of dimimished responsibility".

The court had heard that Mrs Lewis died in West Suffolk Hospital on October 24 last year two hours after her husband of 21 years plunged a kitchen knife with a 19cm blade into her stomach.

The knife penetrated five-and-a-half inches into her body and passed backwards and upwards cutting through her liver and aorta before cutting into a vertebrae in her backbone.

Shortly before the stabbing Mrs Lewis, a supermarket worker, and her 42-year-old husband, who had both been consulting divorce lawyers, had been arguing in the kitchen about who should move out of their home.

Lewis had been using a kitchen knife to cut the wrapping off a joint of beef that he was preparing for a family meal and it was this knife that was used to inflict the fatal wound.

The court heard that Mrs Lewis had been having an affair with her husband's best friend Nigel Langfield and several weeks before her death had told her husband that she wanted to be with Mr Langfield.

At about the same time Lewis had lost his job and was spending his days sleeping and watching television.

He was also taking medication for depression and during his 999 call to the emergency services that was played to the court yesterday he said his medication was "really kicking in" and had "taken over completely".

Giving evidence to the court on the first day of the trial Mr Langfield said he had known Lewis since 1997 and had been his supervisor at work.

He said Lewis had confided in him about problems in his marriage at a time when Lewis didn't know about the relationship between his wife and Mr Langfield.

After his arrest Lewis told the police he had gone to the kitchen bin to throw away the wrapping from the beef and had planned to put the knife in the sink.

As he turned away from the bin his wife had been standing a foot away from him and he had noticed a surprised look on her face.

He claimed she said "you stupid fool" and had looked down. He followed her gaze and saw the kitchen knife in her stomach.

He had immediately pulled out the knife and dialled 999.