Campaigners say they are “hugely disappointed” after senior judges refused to overturn murder convictions in the first test cases after a landmark ruling on the law of ‘joint enterprise’.

One of the cases which could have been considered if the appeals of 13 men heard at the Court of Appeal were upheld, was the murder of Ben Chantler in Folkestone in 2006.

The rulings handed down by Lord Thomas, the Lord Chief Justice of England and Wales, could have paved the way for hundreds of appeals to be lodged against convictions for murders.

It follows a Supreme Court decision in February that the joint enterprise law “could have” been interpreted incorrectly for more than 30 years after a change to the law was made in 1984.

But families say they will continue fighting the decisions and are considering appealing the judgements in the test cases.

Anthony Parsons received a 23-year minimum sentence under the law following the murder of drug dealer Ben Chantler in Folkestone in 2006.

His mum, June Parsons, told the Express at the time of the Supreme Court ruling in February that she had burst into tears when it was read out. She said she found it “really hard to believe that something’s going to go right for a change”.

The joint enterprise law states that defendants can be convicted by having the “foresight” that a killing would take place or at the very least serious harm would be caused – even if they don’t physically take part or are even in the building when it happens.

The Parsons family, who live in Greatstone, have always maintained their son had “no idea” Stuart Benson – who shot Mr Chantler in Denmark Street after a drugs row – was going to commit murder and feared for his own life when Benson told him to drive and park up a few streets away in Sidney Street in a car which needed bump starting.

Jesse Parsons, Anthony’s father, has said the car was a major reason why their son could not have been complicit in planning and carrying out the murder.

The campaign group Jengba (Joint Enterprise: Not Guilty By Association) said it would carry on fighting for the hundreds of families it represents.

In a statement the group said: “Jengba has been fighting for justice for the past six years. During that time we have experienced many setbacks as well as successes.

“The Court of Appeal judgement is a huge disappointment, not just for all the families involved but all those wrongfully convicted ever since the law took a ‘wrong turn’ over 30 years ago.

“It is our understanding the applicants are taking legal advice on whether this judgement can be appealed. Jengba intends to support them in every way we can.”