LONDON — Families and doctors of patients in a persistent vegetative state will no longer need permission from a court to withdraw end-of-life care if both the relatives and the doctors agree, Britain’s highest court ruled on Monday.

The accepted practice in Britain has long been that nutrition and fluids could not be withheld from a patient in a vegetative state without the approval of a specialist tribunal, the Court of Protection. But that approval process can take months or years, and cost health authorities thousands of pounds in legal fees.

Decisions on whether to withdraw end-of-life care are made for thousands of patients each year, the National Health Service reported, though it was not clear how many were in a persistent vegetative state, or in how many cases the families and doctors were in agreement.

The Supreme Court ruled that when there was a disagreement, the question would still have to be decided by the Court of Protection.