Protesters taken to court after preventing a deportation flight from taking off from Stansted Airport are to challenge their convictions at the Court of Appeal.

The so-called Stansted 15 cut through the Essex airport’s perimeter fence and locked themselves together around a Boeing 767 jet chartered by the Home Office to transport people from UK detention centres for repatriation to Africa.

They were later convicted at Chelmsford Crown Court of an offence arising out of the March 2017 incident – three were given suspended jail sentences, and the other 12 were handed community orders.

In August last year, their lawyers announced the activists had been granted permission to appeal against their convictions.

The three-day appeal, starting in London on Tuesday, will be heard by the Lord Chief Justice Lord Burnett, sitting with Mr Justice Jay and Mrs Justice Whipple.

The protesters, who all pleaded not guilty, were convicted in December 2018 of the intentional disruption of services at an aerodrome under the Aviation and Maritime Security Act 1990. They were sentenced in February 2019.

When sentencing them, Judge Christopher Morgan said he accepted their intentions were to demonstrate, but stressed that they were still convicted of a “serious offence” and while their intentions reduced their culpability the “harm in this case is great”.

In a statement ahead of their appeal, members of the Stansted 15 group said their “peaceful” action “prevented people from being deported to places they were not safe”.

“These people are friends, family members, neighbours, mums and dads of young children,” the statement said.

The group added: “We felt compelled to act as we had credible and reliable information about specific individuals who were yet more victims of the UK’s brutal deportation system.

“We should not have been charged with a terror-related offence, let alone found guilty and we hope that the Court of Appeal will overturn our convictions.”

Lawyers for the group are expected to argue the legislation used to convict the 15 is rarely used and not intended for this type of case, and that the Attorney General – who is required to sign off on the use of this legislation – should not have granted consent.

Raj Chada, a partner at Hodge Jones & Allen – which represents the group, said: “The Stansted 15’s actions are not covered by the terms of this legislation, nor should the Attorney general ever have been given consent.

“There will be a chilling effect on the noble tradition in the UK, of dissent and direct action, if terror related offences are used against peaceful protestors.

“Most importantly, there people who were due to be deported that night, but who the courts now accept have a right to stay. That would not have happened but for the actions of the Stansted 15”.

The 15 are: Helen Brewer; Lyndsay Burtonshaw; Nathan Clack; Laura Clayson; Melanie Evans; Joseph McGahan; Benjamin Smoke; Jyotsna Ram; Nicholas Sigsworth; Melanie Strickland; Alistair Tamlit; Edward Thacker; Emma Hughes; May McKeith and Ruth Potts.