Families fighting eviction from the UK's biggest illegal traveller site were tonight manning "barricades" after an appeal court ruling left them at the "end of the road".
Residents of the Dale Farm site near Basildon, Essex, said they had gone into "lockdown" and were preparing to "fight off the bailiffs".
A Court of Appeal judge today refused travellers permission to continue their legal fight against Basildon Council.
Lord Justice Sullivan said there was no evidence likely to persuade appeal judges that the council's decision to enforce eviction notices was "unlawful".
Lawyers representing the council said officials were making preparations to take action at the site, said to contain more than 80 families on 50 plots.
A spokeswoman for support group Dale Farm Solidarity said residents and supporters had gone into "lockdown" in "anticipation of an eviction".
"Today the Dale Farm community were rejected the right to appeal," said the spokeswoman.
"In response to this news, residents of Dale Farm and their supporters reinforced the perimeter of the 50 plots, which house 83 families, and placed the entire site into lockdown in order to resist eviction."
Dale Farm resident Kathleen McCarthy added: "The barricades are all that stand between us and homelessness now... We'll have to fight off the bailiffs."
Candy Sheridan, vice-chair of the Gypsy Council and an adviser to the Dale Farm travellers, said of Lord Justice Sullivan's ruling: "It seems like the end of the road."
Basildon Council's Conservative leader Tony Ball tonight said Dale Farm residents had been "living on borrowed time" and urged them to leave "peacefully and in a safe and orderly fashion".
"The so called supporters should also pack up their belongings and leave the site. If they have the travellers' best interest at heart they will either leave the area now or confine their activities to helping the travellers to leave over the coming days," he said.
"I am particularly concerned by reports that barricades have been strengthened over the weekend. This flies in the face of common sense."
He said evictions would take place as a "at a time of (the council's) choosing" and added: "Our job is now to clear this site in a safe and dignified manner and this is what we intend to do."
Travellers moved to the greenbelt site a decade ago after buying land and set up homes without planning permission.
They have been fighting eviction through the courts for more than six years and say they will be forced to live in supermarket car parks or on roadsides if they have to leave.
In the latest legal battle, lawyers had argued that the council's decision to enforce eviction notices was unreasonable and a breach of human rights legislation.
They said the 400 residents of Dale Farm, who included about 100 children, had not been offered suitable alternative accommodation.
Barristers also argued that the council had not taken account of vulnerable residents or children whose schooling would be disrupted if families were evicted.
But last week a High Court judge rejected the arguments and dismissed applications for a judicial review of the council's decision to enforce eviction notices.
Mr Justice Ouseley said the council had acted lawfully and gave officials the go-ahead to clear most of the site.
Lawyers for the travellers today asked Lord Justice Sullivan for permission to appeal against that ruling.
Lord Justice Sullivan refused their application. The judge said said he had the "greatest sympathy" for Dale Farm residents. But he said Mr Justice Ouseley had delivered a "comprehensive" judgment and had "not erred".
He said the courts had to examine the lawfulness - not the merits of the council's decision - and travellers had not produced evidence likely to convince appeal judges that the decision was unlawful.
Council officials have agreed that a few caravans - plus fences - can stay at the site.