Fifteen protesters who cut through Stansted Airport’s perimeter fence and locked themselves together around a chartered deportation plane have been found guilty of an aviation security offence following a nine-week trial.

Prosecutor Tony Badenoch QC earlier told Chelmsford Crown Court that the group “placed the safety of the airport in a likelihood of danger” through their actions.

A spokesman for the Crown Prosecution Service (CPS) said on Monday that all defendants had been convicted of intentional disruption of services at an aerodrome, contrary to section 1 (2) (b) of the Aviation and Maritime Security Act 1990.

The Boeing 767 jet targeted by the group, operated by Titan Airways, was chartered by the Home Office to transport people from UK detention centres for repatriation to Nigeria, Ghana and Sierra Leone and the offence took place on March 28 2017.

Judith Reed, of the CPS, said after guilty verdicts were returned in the trial: “Through their actions, these defendants intentionally grounded a Boeing 767 and caused significant disruption at Stansted Airport.

“Fifteen protesters used equipment such as industrial bolt cutters, chains, expanding foam, scaffolding poles and lock box devices to prevent the take-off of a plane.

“These people placed themselves, the flight crew, airport personnel and police at serious risk of injury or even death due to their actions on the airfield.

“The CPS worked with the police to build a strong case which reflected the criminality of the defendants’ actions, regardless of their motivation.”

In a statement issued by campaign group End Deportations, the so-called Stansted 15 said: “We are guilty of nothing more than intervening to prevent harm.

“The real crime is the Government’s cowardly, inhumane and barely legal deportation flights and the unprecedented use of terror law to crack down on peaceful protest.

“We must challenge this shocking use of draconian legislation, and continue to demand an immediate end to these secretive deportation charter flights and a full independent public inquiry into the Government’s ‘hostile environment’.

“Justice will not be done until we are exonerated and the Home Office is held to account for the danger it puts people in every single day.”

End Deportations said that a man who was set to be deported on the flight has since been granted a right to remain in the UK.

Raj Chada, partner from Hodge Jones & Allen who represented all 15 of the defendants, said: “We are deeply disappointed by today’s verdicts.

“In our view it is inconceivable that our clients were charged under counter-terrorism legislation for what was a just protest against deporting asylum seekers.”

Shami Chakrabarti, Labour’s shadow attorney general, said: “What a sad International Human Rights day, when non-violent protesters are prosecuted for defending the Refugee Convention, and are treated like terrorists.

“Labour in government will review the statute book to better guarantee the right to peaceful dissent.”

The defendants, aged between 27 and 44, will be sentenced on February 4 at Chelmsford Crown Court.

They are: Helen Brewer, 28; Lyndsay Burtonshaw, 28; Nathan Clack, 30; Laura Clayson, 28; Melanie Evans, 35; Joseph McGahan, 35; Benjamin Smoke, 27; Jyotsna Ram, 33; Nicholas Sigsworth, 29; Melanie Strickland, 35; Alistair Tamlit, 30; Edward Thacker, 29; Emma Hughes, 38; May McKeith, 33 and 44-year-old Ruth Potts.

Twelve of the defendants’ given addresses are in north London, Burtonshaw’s is in Brighton, Potts’s is in Bristol and McGahan’s is in Reading.

• APnews