Protesters who broke into Stansted Airport to stop a plane deporting people to Africa will face no further action through the courts.
The group, known as the Stansted 15, cut through the perimeter fence and locked themselves together around a Boeing 767 jet in 2017.
They won an appeal against their convictions last month.
On Thursday, a spokeswoman for the Crown Prosecution Service said it would not appeal against the decision.
“There will be no further action on this case,” the statement added.
The jet the group surrounded in March 2017 had been chartered by the Home Office to transport people from UK detention centres for repatriation to Nigeria, Ghana and Sierra Leone.
The protesters put their arms inside pipes which were then filled with expandable foam, and secured themselves around the nose wheel and wing of the aircraft, Chelmsford Crown Court was told during their trial.
All 15 were convicted of the intentional disruption of services at an aerodrome, with three given suspended jail sentences, and the other 12 were handed community orders.
At the appeal hearing in November, lawyers for the activists argued the legislation under which the 15 were convicted – the Aviation and Maritime Security Act (Amsa) 1990 – was rarely used and not intended for this type of case.
The Stansted 15’s barristers argued that the Amsa law was intended to deal with violence of the “utmost seriousness”, such as terrorism, not demonstrators.
In his judgement, given in January, the Lord Chief Justice said they “should not have been prosecuted for the extremely serious offence”.
Sitting with Mr Justice Jay and Mrs Justice Whipple, Lord Burnett said the protesters’ “conduct did not satisfy the various elements of the offence”.
“There was, in truth, no case to answer,” he said.
The CPS had 28 days to consider an appeal.
The 15 are: Helen Brewer, 31; Lyndsay Burtonshaw, 30; Nathan Clack, 32; Laura Clayson, 30; Melanie Evans, 37; Joseph McGahan, 37; Benjamin Smoke, 29; Jyotsna Ram, 35; Nicholas Sigsworth, 31; Melanie Strickland, 37; Alistair Tamlit, 32; Edward Thacker, 31; Emma Hughes, 40; May MacKeith, 35; and Ruth Potts, 46.
Mr Smoke tweeted: “We can finally say… IT’S OVER!!!!!!”
In a statement on behalf of the group, he added: “Following the Court of Appeal’s verdict last month which stated there was, in truth, no case to answer, we are of course overjoyed that the CPS have today decided to take no further action.
“After four long years, we finally have some justice, but there are tens of thousands of people who have been swept up and aside by our draconian and callous immigration system who still await theirs.
“We will not stop fighting until the hostile environment is ended, until the brutal practices of raids, detention and deportations are halted and until justice is done for all.”