Lawyers for Co Mayo farmer Padraig Nally have been refused leave to appeal against his conviction for manslaughter and the severity of his sentence.
Nally (61) was jailed for six years for killing Traveller John Ward in October 2004.
The bachelor farmer shot Ward twice and beat him with a stick up to 20 times when he found him trespassing in his farmyard at Cross.
At the Central Criminal Court in Dublin Mr Justice Paul Carney said he could not look Ward's widow in the face if he accepted the appeal application.
"What it comes down to in this circumstance is that I am asked for leave to appeal as far as conviction is concerned to satisfy on the basis that the jury were not consciously and deliberately provided with the infrastructure to bring in a perverse verdict.
"I don't believe that I could look Mrs Ward and her 11 children in the face and say that."
The judge told the court that the trial of 61-year-old Mr Nally from Cross in County Mayo for the murder of 42-year-old Mr Ward was one of the most divisive cases in the history of the state.
"This was quite an exclusive trial in which the people of Ireland divided themselves on social lines. It was a highly emotional and fraught trial."
Nally was found not guilty of murder in July but guilty of manslaughter at the Central Criminal Court sitting in Castlebar, Co Mayo.
Mr Justice Carney said it was the most difficult case he had been required to sentence.
Counsel for Nally Brendan Grehan applied for leave to appeal on the basis that the jury had not been allowed to consider the killing was committed out of self defence.
"In terms of conviction hearing and conviction grounds I'm seeking to appeal the matter on the basis that your Lordship (Mr Justice Carney) usurped the constitutional function of the jury by refusing to permit them to consider a not guilty verdict," Mr Grehan said.
"Are there no circumstances under which what we are dealing with can be described as a lawful killing?" he asked. "Mr Nally was acting out of self defence where two people were on his property."
Briefly outlining details of the killing which took place at Nally's farmhouse at lunchtime on October 14th, 2004, Mr Justice Carney said the 42-year-old victim was attacked as he retreated from the property.
The judge said Ward had been wounded by a shotgun blast before the farmer attacked him a second time.
He also told the court that during the trial he was not referred to a line of authority from Supreme Court rulings and decisions in the neighbouring jurisdiction, used in any kingdom, that would allow him to direct the jury to consider a verdict be it on self defence.
Nally appeared in court dressed in a shirt and jacket and stared forward as the hearing went on.