A builder who killed his lover's estranged husband has been cleared of murder.

David Armstrong, 39, grabbed a kitchen knife and stabbed Anthony Banks to death when the jilted husband broke into his house through a window.

Mr Banks, 43, collapsed and died outside but Armstrong was cleared of murder and manslaughter after a jury decided he acted in self-defence.

Mr Banks had broken in twice before, smashing up the flat with a hammer and assaulting his wife Barbara Banks because he was devastated at the break-up of their 24-year marriage.

The father of two from Whitehawk, Brighton, had made threatening phone calls to Mr Armstrong, a former friend and workmate, and had taken drink and drugs.

Armed with a knife, he went to the house in Mill Road, Lewes, where Mrs Banks was also living, and tried to break down the front door while shouting Mr Armstrong was "a dead man". But when he smashed a window and tried to crawl through he was stabbed at least five times in the head and neck.

Richard Anelay QC told Lewes Crown Court Mr Banks tried to get into the house after smashing the window with a dustbin lid.

He said: "A neighbour heard a woman screaming hysterically and saw Tony Banks step back on to the ground staggering around with a lot of blood spurting from his mouth and collapse on to the floor and after a couple of jerks was still."

Giving evidence, Barbara Banks, who left Armstrong after the stabbing, told the court: "I saw his arm come up with a knife. They weren't jabs - they were heavy.

"I saw them go across Tony's face. He fell back out of the window. I rang an ambulance. I think he asked how I felt about what he had done.

"I said something like 'You had to do something but you didn't have to use a knife'."

William Lowe QC, defending, read part of the statement Mrs Banks made soon after the stabbing which described her estranged husband as "screaming like a madman" as he tried to get into the flat.

When read part of her statement which said "David did it to save the two of us from Tony" and "Something had to happen to stop him getting into the flat - it was him or us," Mrs Banks replied: "Yes, but there are other ways."

Armstrong said in taped police interviews: "I just panicked because he was going to kill us. I picked up the knife. I didn't mean to hurt him. I just wanted to prod him out of the window."