The man behind bars for plotting to murder former UDA terror boss Johnny "Mad Dog" Adair and his right-hand man has failed to lodge his appeal on time.

Anton Duffy, 39, along with his cousin Martin Hughes, 36, and Paul Sands, 32, conspired to murder Mr Adair and Sam "Skelly" McCrory while police and security services mounted a ten-month surveillance operation to foil the plot and bring them to justice.

Ringleader Duffy wanted to get his hands on an AK 47 assault rifle as part of the plot. He was heard on police surveillance tapes referring to the weapon as the "big fella".

The jury found the three men guilty of the murder plot. Duffy and Hughes were also convicted of related terrorism charges. Duffy was sentenced to 17 years behind bars, Hughes was handed an 11-year sentence and Sands was jailed for ten years.

Duffy had lodged his intention to appeal after he was jailed but it has now emerged he did not lodge his grounds for appeal on time. It has now been thrown out as a result.

A spokesman for the Scottish Judiciary said on Wednesday that Duffy's appeal has been "deemed abandoned" after he "failed to lodge the grounds for appeal within the legal time frame".

The nine-week trial last year heard evidence that the three men planned the hit while parked outside Mr McCrory’s home in Ayrshire. Detectives bugged the car they were in and followed them as they drove from Glasgow.

Duffy was taped saying he wanted to "blast him in the ear" as he sat in a car outside Mr McCrory’s home with Hughes and Sands.

The High Court in Glasgow heard Duffy and Hughes drove from Glasgow on October 1, 2013 in a silver Mercedes 4x4 and met up in Ayrshire with Sands, who knew Mr McCrory well.

Extracts of the tapes of the three meeting and driving to where the former senior Loyalist lived in Ayrshire was played in court.

The court was also told Duffy was heard saying they needed “a sawn-off and a revolver as the back-up".

As the 4x4 approached the street in which McCrory lives, the jury was told Sands said: “This is the road he walks every single day. You can't go wrong. It is a straight road."

It was intelligence from MI5 that alerted police to 39-year-old Duffy, who at that time was in prison for having a loaded revolver in a Glasgow nightclub. He and his associates were placed under surveillance for ten months.

Undercover officers watched Duffy while he was on home leave with his home bugged and his cousin's car.

Sands was a so-called friend of Mr McCrory and knew where he lived and his movements. The plan was to make this murder look like a random shooting.