A judge showed mercy today to a devoted husband who killed his seriously ill wife to spare her from the degenerative effects of multiple sclerosis (MS).

Robert Cook acted on the wishes of Vanessa Cook when he placed a plastic bag and pillow over her face after she had taken an overdose of pills on October 19 2006.

After admitting manslaughter on the grounds of diminished responsibility and aiding and abetting his wife's suicide, a judge sentenced 60-year-old Cook to 12 months jail, suspended for two years.

Lewes Crown Court heard Mrs Cook, 55, had asked her husband to help end her life after she had become drowsy from the overdose so that her life could end in dignity.

The couple, described as "peas in a pod", were said to have been devoted to each other throughout 29 years of marriage, during which time they only had two rows.

But the health of Mrs Cook, who had a history of depression, deteriorated after she was diagnosed with MS in 2003 following years of showing symptoms of the condition.

The court heard the couple, who had no children and lived in Camber Close, Crawley, West Sussex, had spoken several times about ending her life once MS had taken hold.

Mrs Cook had expressly told her husband not to call the emergency services until he was certain she had died, it was said.

Prosecutor Christine Laing QC said: "Mr Cook said he loved his wife very dearly and that he felt shocked at what he had done as it was against his own principles but it was what she wanted him to do.

"Her condition was deteriorating and he did not want her to suffer.

"It was his wife's suggestion to put a bag over her head after seeing it done on television, in the event that the overdose alone would not work."

After she had died, Cook called the emergency services at 12.20pm and he led police officers to their bedroom where his wife lay beneath the duvet with a white plastic bag wrapped under her chin.

During attempts by the officers to resuscitate her, Cook told them to leave her alone, saying: "She wouldn't thank you for your efforts."

Cook, who has no previous convictions, was arrested on suspicion of murder and during police interview he broke down as he said he would have to "live with what I've done".

Referring to the killing, he also said: "It's not what they show you on the TV. It doesn't take a couple of minutes. It takes longer."

Two notes in Mrs Cook's handwriting expressing her wish to die were found at their house.

A post-mortem examination carried out the day after her death found the cause of death was due to mixed drug intoxication and the plastic bag over her head.

Ms Laing said: "After being arrested, in interview Mr Cook described her medical condition, her multiple sclerosis and previous suicide attempts.

"He said that on October 19 she had woken and asked him to end it all and asked him to put a pillow or bag over her head once she was dopey. He also dissolved some tablets for her once she was unable to swallow.

"He said he asked her if she was really sure she wanted him to do this and she nodded yes."

Ms Laing said Mrs Cook's brother and sister had both written to the officer in the case outlining their support for Cook.

"It was a loving, close and long-standing relationship and they understood the actions that he took," Ms Laing said.