The decision to extradite Babar Ahmad to the US to face terror charges has been condemned as "shameful" and "disappointing" by family and friends as justice campaigners renewed their calls for extradition arrangements with America to be reviewed.
Computer expert Ahmad, who has been in jail without trial since 2004 while fighting extradition, is accused of being involved in a website which encouraged terrorism and which, while operated from London, was hosted in the US.
In a statement, Ahmad who has pleaded to be charged and tried in Britain, said: "By exposing the fallacy of the UK's extradition arrangements with the US, I leave with my head held high having won the moral victory."
Karl Watkin, the British businessman who has been campaigning to have the men tried in British rather the USA, said he was not "suprised" by the verdict but condemned the UK legal system.
Mr Watkin said he was "extremely frustrated but not at all surprised" by the judges' decision.
"I have no regrets over pursuing a private prosecution - it was the right thing to do," he said.
"No ifs, no buts - British citizens should be tried in Britain for crimes perpetrated in Britain and in circumstances where the evidence is found in Britain.
"What's more, I know tens of thousands of principled British people agree with me."
Ahmad and Syed Talha Ahsan wanted their removal stopped so that they could challenge a decision by the Director of Public Prosecutions not to allow Mr Watkin to bring private prosecutions against them in the UK.
Mr Watkin went on: "Allowing the US to expand its extraterritorial reach by claiming jurisdiction over internet servers is undermining British and international justice.
"Servers are commonly cloud-based - which is where the UK's judicial and government leaders have their heads today.
"British extradition law urgently needs updating to assert jurisdiction over the territory in which cyber crime is physically committed.
"No matter how much the public and their representative MPs protest at today's outrage, no British court will ever try these two suspects.
"RIP British justice."
Babar Ahmad's father Ashfaq said: "After over 40 years of paying taxes in this country, I am appalled that the system has let me down in a manner more befitting of a third world country than one of the world's oldest democracies.
"We will never abandon our struggle for justice and the truth will eventually emerge of what will be forever remembered as a shameful chapter in the history of Britain."
Mr Ahmad, 77, of Tooting, south-west London, said his son should be tried in the UK.
"All the evidence was available against him in this country," he added. "I cannot understand why he should be sent to the United States."
He went on: "Babar has been in prison for eight years without trial."
Mr Ahmad said he expected his son to be extradited quickly, adding: "I think they want to get rid of him as soon as possible."
Emma Norton, legal officer for human rights group Liberty, said: "Mr Ahmad's alleged offences happened in this country - it beggars belief that he won't be tried here.
"This is yet another example of the dangers of our flawed extradition arrangements. Isn't British justice - so admired around the world - capable of dealing with crimes committed in the UK by its own citizens?"
Shadow justice secretary and Tooting MP Sadiq Khan said he expected both Ahmad and Ahsan to accept a plea deal when faced with the US justice system.
"The way criminal cases work in America means that defendants facing a trial are advised to plea-bargain," he said.
"I predict that both my constituents will do the same as all the other British men extradited to the USA have done and plead guilty.
"It is a big risk pleading not guilty.
"My understanding is that the consequences of this include the threat of life in solitary confinement without parole, should they lose a trial.
"If those are the stakes which pleading not guilty involve, then it is no wonder that over 97% of defendants accept a plea bargain - regardless of how confident or determined they are to stand trial."
Mr Khan went on: "Family, friends and campaigners of Babar Ahmad and Syed Talha Ahsan are devastated by the judgment at the High Court today.
"The families of my constituents, Babar Ahmad and Syed Talha Ahsan, have worked tirelessly to have them tried in a British court and it would appear that their extradition to American is now imminent.
"It is important to remember that at no stage have my constituents ever fought against standing trial.
"They understand that they face very serious charges, but they have always believed that it should be in a British court - and not an American one - where they should stand trial."
Babar Ahmad is a martial arts devotee who has shrapnel in his skull after fighting with Muslims in the bloody Bosnian war.
Details of his life were disclosed last year when four police officers were accused of assaulting him during a dawn raid at his home in Tooting, south London, on 2 December 2003.
The officers, from the Metropolitan Police Territorial Support Group, were all cleared but Ahmad was awarded £60,000 compensation two years before the trial after Scotland Yard admitted he was badly treated.
Before launching their raid they were briefed that Ahmad had received terrorist training and fought overseas in support of jihad - holy war.
They were also told Ahmad had been trained by al Qaida in armed and unarmed combat.
Ahmad, who admitted volunteering to fight with Muslims abroad, trained in martial arts several times a week and was months away from getting a black belt in kung fu when he was arrested.
A computer expert, he admitted fighting in Bosnia three or four times during the bloody 1992-1995 war after first fighting when he was 18 - but he insisted he was not an "al Qaida superman".