A father accused of murdering his dying son relived the harrowing moment he smothered the boy with a pillow.

Former SAS soldier Andrew Wragg called his wife to say he was going to "end the boy's suffering", before placing a pillow over his face, a court heard.

Fighting back tears, Wragg, 38, told how he looked into his son Jacob's eyes and asked: "Have you had enough son?"

Believing ten-year-old Jacob could no longer recognise him, Wragg killed the youngster and then sat cuddling his lifeless body, Lewes Crown Court heard.

"I looked into his eyes and he just stared at me," Wragg told the jury. "I did not think he was happy. There was nothing left. He was gone."

Wragg denies murdering Jacob, who was suffering with the rare degenerative disease Hunter syndrome and was not expected to live past his midteens, on July 24 last year at the family home in Henty Close, Worthing.

But the defendant admits manslaughter on the grounds of diminished responsibility, claiming he was suffering an abnormality of mind when he killed Jacob in what he later claimed was a "mercy killing".

Giving evidence for the first time at a retrial in the case yesterday, Wragg said he telephoned his wife Mary on the day of Jacob's death to reveal his intentions to kill the boy.

He said: "I tried to explain what I had seen in his eyes, and that I felt he had come to the end of the road.

"I did not want him to suffer any more. I said he could not tell us what pain he was in. I said I thought I would go away on holiday and when I came back, take him away with me and stop it. I said I was going to take him away and end his life, not for me or for you but for Jacob."

Mrs Wragg replied: "Why wait", the defendant claimed.

The prosecution says Jacob's murder was a "selfish killing" by Wragg who could no longer cope with the boy's condition.

Yesterday in court, Wragg said: "It is insulting to me and to Jacob to suggest that what I did was selfish. It has been said more than once that I did not do it for me or for her (Mary) but for Jacob and that is the way it will always be."

Michael Sayers QC, defending, asked Wragg if he felt Jacob still recognised him. The defendant replied: "No, I don't think he did."

The defendant said he and his wife were left in an "impossible and hopeless" situation in caring for Jacob. On the day he killed the boy, he told a friend: "You don't know how hard it is. It's 24/7."

The trial was adjourned until tomorrow.