The camp, situated close to the landfall and original onshore route of the Corrib gas pipeline, was established two years ago, shortly before the Rossport Five were jailed.

An interim injunction restraining camping and habitation of the land was obtained by Garvey, Smith and Flanagan Solicitors, acting on behalf of Mayo County Council, at Castlebar district court on Friday and was issued to residents of the camp later that evening by two officials from Mayo County Council.

In a letter delivered to the camp on Friday night, Leslie McNicholas, an engineer in Mayo County Council's planning enforcement unit, states that the camp is "likely to cause irreparable damage to the sand dunes and adjoining landscape".

Mayo County Council will apply to Castlebar circuit court tomorrow to cease what it terms the "unauthorised use and development" of the land, which is located in the Glenamoy Bog complex, a candidate Special Area of Conservation (SAC).

Camp spokesman Bob Kavanagh said he and his fellow participants had a very "low impact lifestyle", a close relationship with the local community, and had been given advice on a number of occasions by the National Parks and Wildlife Service.

The camp, powered by two solar panels, comprises a wooden cabin, several benders (structures made from bent hazel poles), compost toilets, food composting facilities, a water treatment system, pathways and a kitchen.

Yesterday up to 60 Shell to Sea campaigners walked to the site of the proposed Corrib gas terminal at Bellanaboy, north Mayo. The incursion lasted approximately an hour.

Meanwhile, over 1,000 people took part in a demonstration in Dublin city centre yesterday to protest against the routing of the M3 motorway through the Tara-Skryne Valley in Meath.

Protesters marched down O'Connell Street to the Custom House, before delivering a petition to the Department of the Environment with over 50,000 signatures objecting to the destruction of archaeological sites at Tara to make way for the motorway.

Organiser Vincent Salafia said he was very satisfied with the demonstration: "It's gone very well . . . we've had a great turnout, with everyone from college professors to children in prams attending."

He stressed that the TaraWatch group will continue to put pressure on the environment minister to stop the road from being routed through the archaeological site: "We're hoping that John Gormley will reverse the decision, but if he doesn't, we're fully prepared to go to court to stop him from allowing it to go ahead."