Scott Snowden, 39, was jailed for 33 years last summer for masterminding the murder of Thomas Sharkey, 55, his son Thomas junior, 21, and daughter Bridget, eight, in a fire at their home in Scott Court, on July 24, 2011.

Co-accused Robert Jennings, 51 – who set the fire by pouring petrol through the letter box on the instructions of Snowden – was jailed for 29 years.

Mother Angela Sharkey was the sole survivor of the fire.

Following a single judge procedural hearing in April of this year, the pair today (Tuesday) launched their appeal in court. Snowden has lodged an appeal against his conviction, and Jennings against conviction and sentence.

At the time of sentencing, Lord Matthews told the pair as they stood in the dock: “You have been convicted of what is without doubt the most appalling crime.

I have ever been involved with in my professional career, the murder by fire of three quarters of a family.

“One of them Thomas Sharkey senior, who suffered a long and painful death, had been able to live to middle age, but his son Thomas and daughter Bridget were cruelly deprived of any chance in life.

“Thomas, a promising golfer, who had gone abroad to study and to try to fulfil his potential. Who knows what Bridget would have made of herself. She was a typical smiling innocent young girl with all her life before her.” Snowden shares the dubious distinction of currently serving the longest sentence handed down in a Scottish court along with Colin Coats, who murdered financial adviser Lynda Spence.