The Supreme Court has voted by 5-2 to extradite Wikileaks founder Julian Assange to Sweden to answer questions about an alleged sexual assault.
Mr Assange faces allegations from two separate women from a visit to Stockholm in Stockholm in 2010, which he says are politically motivated.
Lawyers for Mr Assange demanded the UK's highest court block the removal as the European Arrest Warrant on which it was issued was "invalid and unenforceable".
The case hinged on the judicial authority of the prosecutor issuing the arrest warrant under the Extradition Act 2003.
Mr Assange's legal team argued the Swedish prosecutor was an unsuitable figure to issue the warrant because they are a party in the case, but the Swedish Prosecution Authority successfully argued the term "judicial authority" had a wide meaning.
The judgement means it will not be possible for those resisting extradition in the future to deny that European prosecutors have the right to issue a warrant.
But Mr Assange's legal team raised the prospect of an even more protracted process today when they suggested they may ask for the case to be re-opened on the basis that the ruling was made on a point not argued in the appeal hearing. They have 14 days to decide.
They can also appeal to the European Court of Human Rights (ECHR), although it can decide not to take the case.
The decision is just the latest dramatic twist for a figure who divides opinion.
Mr Assange originally hit the headlines because of his association with Wikileaks, which dumped diplomatic cables and sensitive information about American military conduct in the Middle East on the internet in 2010.
Since then, Mr Assange has lost many of his original allies, with the New York Times and the Guardian distancing themselves from him. He has also started a discussion show on Russia Today, prompting accusations of hypocrisy.