A woman who stabbed her husband to death left a note saying she had “taken so much abuse over the years” and that she accepted “her punishment”, a court has heard.

Penelope Jackson, 66, is accused of murdering her husband of 24 years, the retired army lieutenant colonel David Jackson, in the kitchen of their bungalow on 13 February, Bristol crown court heard. She admits manslaughter but denies murder.

The jury previously heard David Jackson, 78, managed to call 999, telling the operator his wife had stabbed him, before screaming in pain as she allegedly drove the knife into him for the final time at their home in Berrow, Somerset.

On Tuesday, the jury of four men and eight women heard police found a note written on a pad by the telephone when they arrived at the scene.

It read: “To whom it may concern, I have taken so much abuse over the years – look at my records.”

It continued: “But he was a good Daddy. However, the mask slipped tonight. That was unforgivable. I accept my punishment, may he rot in hell.”

Sheila Taylor, Jackson’s ex-wife and his second overall, gave evidence at the trial on Tuesday.

Taylor told the jury that David Jackson left her in 1993 after revealing he had been having an affair with the accused, who he had met working for the military in Grantham, Lincolnshire.

Taylor told the court she had remained in contact with her ex-husband and in the mid-90s he had seemed “very unhappy”.

Taylor said David Jackson feared Penelope Jackson would “destroy him” and “ruin his career”.

Taylor said she asked David Jackson why he did not leave her, to which he replied: “She will do a Bobbitt on me.”

Taylor told the jury this was a “topical” reference to a woman in the US who had cut off her husband’s penis.

Asked by the prosecuting barrister, Christopher Quinlan QC, how David Jackson seemed when he said this, Taylor replied: “He was very frightened. He believed she was capable of carrying that out.”

Earlier in Tuesday’s hearing, Quinlan read a statement to the court that Jackson gave to police after her arrest, claiming David Jackson had been abusive and controlling towards her.

Penelope Jackson said the “extreme violence” had started after the suicide of the victim’s son from his first marriage in 1998.

She said the attack in February had been sparked by a row over food during a Zoom call the couple had with Jackson’s daughter, Isabelle, and her son-in-law.

She said she had gone to bed with a knife under her pillow for protection.

The statement said: “When I woke up I felt I couldn’t do this any more and I intended to take my own life and I planned to slit my wrists.

“I told David I had had enough and was going to kill myself and he said, ‘Get on with it then,’ – I then thought, ‘Why should it be me? It’s you.’”

Jackson claimed the victim had laid down on the spare bed and goaded her into stabbing him.

During the 18-minute 999 call, which was played to the jury on Monday, David Jackson can apparently be heard screaming in pain as the defendant drives a knife into him.

Jackson tells the call handler she stabbed him because “he thought I couldn’t go through with it”.