The director of public prosecutions, Kier Starmer, has advised 20 climate activists to appeal against their convictions.
They were convicted of plotting to break into a power station in 2009.
But the convictions took place while undercover police officer Mark Kennedy had infiltrated the group.
Kennedy was said to have played a key role in orchestrating the plan.
The police are also suspected of suppressing evidence because of what it may reveal about Kennedy’s involvement.
Imperialist tensions are heating up
More Islamophobia in the Tory party