A US federal judge has refused to order doctors to resume feeding Terri Schiavo, the brain-damaged Florida woman whose fate has split her family.
Mrs Schiavo's husband has fought to have the feeding tubes removed
Her parents had failed to prove a "substantial likelihood of success" if the case went back to court, Judge James Whittemore ruled.
President George W Bush has intervened to allow courts to review the case.
Mrs Schiavo, 41, who has been in a vegetative state since 1990, has received no food or water since Friday.
'Apply the law'
In his early-morning ruling in Tampa, Florida, Judge Whittemore wrote that Mrs Schiavo's "life and liberty interests" had been protected by Florida courts, the Associated Press news agency reports.
Despite "these difficult and time strained circumstances", he wrote, "this court is constrained to apply the law to the issues before it".
Lawyers representing Mrs Schiavo's parents, Bob and Mary Schindler, said they were likely to appeal against the decision.
Mrs Schiavo's feeding tubes were removed at the request of her husband.
TERRI SCHIAVO CASE
Feb 1990: Mrs Schiavo collapses
May 1998: Mr Schiavo files petition to remove feeding tube, triggering legal battle
Feb 2000: Court rules to remove feeding tube
Oct 2003: Florida's lower house passes "Terri's Law", allowing governor to order doctors to feed Mrs Schiavo
Sept 2004: Florida Supreme Court strikes down law
Dec 2004: Case goes to US Supreme Court
Jan 2005: Court rejects petition
Mar 2005: Florida court again allows removal of tube. Federal judge turns down parents' appeal
He says she would not want to be kept alive artificially and has no hope for recovery.
Doctors say she could survive several weeks without any food or fluid.
Mrs Schiavo's parents have argued that she responds to them and could improve with treatment.
Her brother, Bobby Schindler, said his family was crushed by Tuesday's ruling.
"To have to see my parents go through this is absolutely barbaric," he told ABC's Good Morning America.
But Howard Simon, director of the American Civil Liberties Union of Florida, praised the ruling.
"What this judge did is protect the freedom of people to make their own end-of-life decisions without the intrusion of politicians," he said, the AP news agency reported.