A London Court of Appeals on Wednesday overturned the “excessive sentencing” imposed on three anti-fracking protesters in Lancashire.

The activists, Simon Blevins, Richard Roberts and Rich Loizou, were convicted of causing a public nuisance for their role in a 100-hour blockade on a drilling site and were handed  a 15-16 month sentence.

Lord chief justice, Lord Burnett of Maldon, called for the immediate release of the prisoners and said the sentences were “manifestly excessive.”

In our judgment the appropriate sentence was a community order with a significant requirement of unpaid work. But these appellants have been in custody now for two weeks, the equivalent of a six-week prison sentence. As a result, and only for that reason, we’ve concluded that the only appropriate sentence is a conditional discharge.

The appeal was supported by the human rights organization Liberty and Friends of the Earth, and the protesters were granted an expedited appeal amid widespread anger at the peaceful protestors initial sentences.

During the appeal it emerged that the trial judge has family links to the oil and gas industry. “Judge Robert Altham’s father and sister run JC Altham and Sons, a company that acts as a supply chain for Centrica, which as invested tens of million pounds in fracking.

The judicial conduct investigations office confirmed that it has received a complaint about Altham and will begin an investigation.