A new action group has been formed to protect a sensitive area of marshland near Camber.
Save Walland Marsh has been established following anger from local people who claim Natural England gave consent to a London Church to hold its annual summer camp on a field behind Pontins holiday centre.
Resident Ludwig Krapf said: “The contrast between an officially declared nature reserve and this new use could not have been starker.
“People in the new houses neighbouring the fields found themselves all of a sudden, and without any notice, bordering on a huge fair with more than 5.000 people parking their cars, camping and glamping.
“Even the Archbishop of Canterbury came to give his endorsement to this outrageous event.”
Protestors say the event posed a threat to rare great-crested newts.
Mr Krapf said: “Various large tents were built with easily the largest tent in England being in the middle.
“Basically everything one would think rare species might be scared away by was there - very loud music, not differing from an ordinary rock concert and the field lit up day and night like a football stadium.
“People next to the event turned to the authorities to ask for an explanation when their houses started to reverberate from the music and also people from the region who care for Walland Marsh and its protected areas wondered how it could be possible that huge lorries, some of them surely over 40 tons, manoeuvred on such a sensitive ground with the newts only confined to the ditches during their breeding time.
“The answers they got from Rother Council or from Natural England were vague and as a whole very unsatisfactory.
Almost the only person who cared and listened to concerns was Rye MP Amber Rudd.
“Now that the action group has been formed we will probably take this to a European level.”
He added: “Walland Marsh has unique and outstanding wildlife. In the early winter huge flocks of Arctic birds use the site.
“As well as great crested newts, the area also houses a fair population of bats. For all these reasons the ground has been officially declared a Site of Special Scientific Interest (SSSI)”.