A vicious son beat his terminally ill father to death after brooding over the way he had treated his mum when their marriage broke down.
Anthony Hughes, 32, hated his father Brian for the collapse of his relationship to Susan 20 years earlier.
But his hatred turned to murder on Easter Sunday following a series of rows just 10 days after he was forced to move back in with his 60-year old estranged father in Darwen, Lancashire.
He jumped on his dad as he lay on a sofa and repeatedly punched him in the face before dragging him outside stamping on his head up to 20 times as he lay on the ground.
While police dashed to the scene, Anthony Hughes rang his mother and said, "I've killed him, he was going to get us. He will never hurt anyone again."
Hughes pleaded guilty to the murder at an earlier hearing at Preston Crown Court. He was ordered to serve a minimum of 18 years and eight months in prison.
Det Insp Andy Hulme said: "This was a cowardly and sustained attack on an innocent man. Anthony Hughes has shown absolutely no regard for his father and now faces a considerable custodial sentence to consider what he has done.''
Judge Anthony Russell QC told Hughes: "For many years you had hated your father from whom you were estranged following the relationship with your mother.
"Your anger boiled up fuelled by drink, insults were exchanged when he got home in the early hours and your anger turned to violence.
"He was in no position to defend himself. He was 60, in poor health with terminal cancer and his mobility was affected.
"He was particularly vulnerable and there was a considerable amount of suffering before his death.
"The attack was brutal and savage and there was a degree of hatred and cruelty."