Top judges have refused to increase the jail term of a mentally-ill Penzance man whose disabled neighbour died after he put a potato into his gas flue.

Daniel James Long Burgess, 38, of Chywoone Avenue on the Gwavas Estate, was jailed for two years and eight months at Exeter Crown Court on February 6. He had admitted the manslaughter of Michael Horner, aged 48.

The Solicitor General, Robert Buckland QC, referred his sentence to London's Appeal Court arguing it was far too soft. His lawyers urged Lord Justice Davis, Mr Justice Holroyde and Judge Christopher Kinch QC to double Burgess' sentence. But the judges disagreed and ruled his punishment was not "unduly lenient."

Mr Horner died at his Penzance home in December 2015 as a result of carbon monoxide poisoning. Burgess had placed a potato and expandable foam into Mr Horner’s boiler flue, Lord Justice Davis told the court.

Mr Horner, who had Huntington's disease, lived alone in a ground floor flat with a gas boiler, which had a meter box and flue on an external wall. There had "lately been a falling out" between Burgess and Mr Horner, said the judge.

A video on Burgess' phone recorded a confrontation shortly before Christmas where he threatened his disabled neighbour, saying "I will f*** you up." On Christmas Day, Mr Horner discovered that his central heating was not working and found that the gas supply lever had been turned off.

The same happened on Boxing Day, but this time the doors to his flat had been filled with super glue and expanding foam to stop them opening. Police community support officers spoke to Burgess but, on December 29, Mr Horner was found dead in his living room. The gas flue had been blocked with expanding foam and a large potato.

And in an "unlucky coincidence", a safety cap was missing from the boiler, meaning the fail-safe did not operate. A post-mortem found Mr Horner died from the toxic effects of carbon monoxide.

Burgess had previous convictions for criminal damage and arson. A psychiatric report pointed to his "troubled childhood" and "obvious sense of remorse."

He has been diagnosed with paranoid schizophrenia and temporal lobe epilepsy. His long-standing mental illness "may go some way to explaining the somewhat bizarre nature of his actions and his general over-the-top responses in the dispute," said the psychiatrist.

Oliver Glasgow QC, for the Solicitor General, said Burgess knew Mr Horner was "vulnerable" yet he had carried out a "series of hostile actions" as a result of an "apparent feud." He was motivated by a desire for a "kind of revenge."

The QC argued the sentence was "far too low" and failed to deal with the worst aspects of the crime - including the fact Mr Horner lost his life. He added: "Whilst that was not the intention, and never the intention of this offender, the assessment of the gravity of any offence has to include an assessment of the consequences of the deliberate actions. In this case, the result of his deliberate actions was the death of Michael Horner."

Kate Brunner QC, for Burgess, agreed the term was "lenient", but said it fell within the range of options available to the judge.

Lord Justice Davis said it was accepted that "there was absolutely no intention on behalf of Burgess to cause any physical harm at all." But "on the other hand the conduct in question has, however inadvertently, led to the loss of a life."

He said it was a "most unlucky coincidence" that the safety cap had been removed from the boiler.

"Had it remained in place, the boiler would have shut down and no death would have resulted," he added.

Burgess' intention was "simply to cause Mr Horner to have a cold Christmas holiday," said the judge. What he had done was "a very dangerous act" and the sentence was "in our view lenient," said the appeal judge.

But he went on to rule that there was "room for a degree of leniency in this case." Refusing to up the jail term, he concluded: "We are not prepared to categorise this sentence as unduly lenient."