Irish travellers have won an injunction against Basildon Council preventing it from removing buildings from their halting site.
Earlier, around 20 bailiffs arrived at the main gate of the Dale Farm travellers' site in Essex today to start the eviction of up to 80 families living on an unauthorised plot.
The injunction stands pending a hearing on Friday.
Up to 40 supporters of the travellers have gathered under a scaffold watchtower to resist the entry of the bailiffs who have been employed by Basildon Council to remove the travellers from the site in Essex.
Many protesters have chained themselves to obstacles, including cars and barrels containing concrete.
Council leader Tony Ball said the bailiffs would launch the operation to clear the site in a safe manner.
After a brief discussion with travellers' representatives, the bailiffs retreated.
Travellers said they read a health and safety notice and told them they planned to return shortly.
One of the bailiffs spoke to the protesters through a megaphone while activists shouted "scum" at him and his men.
The move came after planned last-minute talks between the council and the travellers broke down this morning.
A council spokesman said: "The purpose of the meeting was to discuss the health and safety issues on site, but unfortunately these talks were cancelled by the travellers.
"We therefore asked our contractors to approach the site entrance to have these discussions with the travellers and protesters directly.
"The council is committed to carrying out a safe and lawful site clearance and this approach is part of that."
Basildon Council leader Tony Ball said the full operation to clear the site could last as long as six to eight weeks.
"I am very disappointed that we have come to where we are today," he said.
"I would much rather that we reached a much more peaceful solution, and I am still hoping that once our bailiffs will move on site they will be received in a peaceful manner and that the operation will go ahead as we would like it to proceed."
He added: "Our operatives, when they begin the site clearance, which will be today, will do everything they can to make sure it's done in a safe and professional manner."
Basildon Council said it had offered accommodation to all of the families affected.
Mr Ball said he understood that the travellers on the illegal site were outnumbered by the 50 to 60 supporters protesting against the eviction.
He said: "My personal concern is the intervention of outsiders, who maybe have their own agendas and again in my view not the interests of the travellers at their heart, certainly raises the risk of there being a disturbance."
Travellers inside Dale Farm reacted angrily to claims that only activists remained inside the wire.
Kathleen McCarthy said: "The elderly and sick are here and we will stay. That bluff won't work with us."
Campaigner Grattan Puxon condemned the council's approach to the cancelled meeting.
He said: "They only wanted to talk about peaceful eviction, not an alternative site for the homeless, so as far as we're concerned negotiations are off and we're preparing for the bailiffs to move in."
One supporter, who gives her name only as Marina, said: "They made it quite clear they were coming back and we made it clear the only way we will negotiate is if an alternative site is provided.
"It is quite clear we can't stop the bailiffs coming in because points of the site are vulnerable.
"We believe they will take an alternative route to the main gate.
"Our aim then will be to prevent them creating a sterile area within the site."
The protesters erected reinforced barricades and built a new wall, and some chained themselves to obstacles to keep the teams of bailiffs out using "peaceful resistance".
Two supporters of the travellers, giving their names as Dean, 29, and Emma, 18, handcuffed themselves to a pole concreted inside a barrel behind the gate to the site.
Dean said: "I have studied what's going on here long and hard and believe when the law is used for wrong, civil disobedience is the only way to oppose it.
"The idea is the bailiffs cannot open this gate without killing us both. We'll sleep here for weeks if we have to."
Paintings of children and a banner calling for "Human rights for Dale Farm" were put up outside the main barricade.
There was also a sign warning about the activists chained to a barrel, stating: "Danger of death. Behind this gate a woman is attached by her neck. If you attempt to open this gate, you will kill her."
As speculation mounted inside the camp that the clearance was imminent, resident Elby, 28, said she was no longer scared.
She said: "We've been worrying about this for weeks and we can't carry on being terrified forever. I'm ready to face the bailiffs and whatever will be will be.
"Most of the people at Dale Farm have lived through evictions before so we have learnt to expect rough treatment.
"What concerns me is where me and my family will go once they kick us out of our homes. I have nowhere and nothing apart from my home on this site."
One protester called Ruth, who chained herself to a car, said: "There are people here from all over the world and the travellers have made us so welcome.
"It has become increasingly difficult for travellers to find a site in recent years. Planning law is very discretionary and we do not feel it's being used fairly."
The protesters are demanding that Basildon Council provide 62 plots to temporarily house those made homeless while planning permission is sought for other sites.
Supporters delivered a large amount of supplies, including crisps, bread, tinned fruit, biscuits, peanuts, dried apricots, orange juice and toilet paper, to the site through the main gate this morning.
Meanwhile, elderly traveller Mary Flynn mounted an unsuccessful final legal challenge to the clearance in London's High Court today.
The 72-year-old, who has been a crucial protagonist in the High Court battle, suffers from breathing problems and argued that her poor health should have a bearing on the clearance.
The Government turned down an offer by the United Nations to help broker an agreement between the travellers and the council, it was claimed today.
Jan Jarab, the European representative of the UN High Commissioner for Human Rights, told the Guardian: "We offered to be part of a negotiation to try and arrive at a less dramatic solution at Dale Farm.
"There was communication between the British Government and our headquarters, but it was made clear to us that we would receive a letter that that offer was rejected.
"It is terribly sad and I am disappointed. A forced eviction is a dramatic event for the people concerned."
Mr Jarab told the paper the Dale Farm clearance operation was "very symbolic" and sent a message across the European Union that the Government backed an "eviction-based approach".
Resident Kathleen McCarthy said: "This was our last chance to resolve it through the courts and negotiations have failed. But we were expecting it because nobody is on our side.
"Now our only chance is peaceful resistance and this just makes us more determined to stop bailiffs."
Bryan Lecoche, of bailiffs Constant and Company, told the demonstrators: "As you are fully aware, there is a legal judgment that allows Basildon Borough Council to restore this area of land back to the green belt.
"We have been facilitating your peaceful protest up until now, but I and the council have some major health and safety concerns that I wish to discuss with you, namely that you have deliberately blocked, and are by your actions obstructing, the emergency access road.
"In addition, I'm concerned that the structure that has been erected has the potential to put people's lives in danger.
"I'm concerned for your wellbeing and the wellbeing of the council's agents who have been instructed to restore the land.
"In the interests of health and safety, is there anything I can say or do that will persuade you to remove yourselves in an orderly manner?"
Electricity supplies to Dale Farm appeared to have been cut shortly before 4pm as televisions and other appliances went dead.