* Radical Islamists attacked soldier on busy London street
* Killing shocked Britain, triggered anti-Islamic backlash
* Soldier Lee Rigby was 25-year-old Afghan war veteran (Adds remarks by judge, family reaction)
By Costas Pitas
LONDON, Feb 26 (Reuters) - Two British Muslim converts were sentenced to life in prison on Wednesday for hacking a soldier to death on a London street in broad daylight, a gruesome killing that horrified the nation and provoked an anti-Islamic backlash.
Michael Adebolajo, 29, and Michael Adebowale, 22, were convicted by a jury in December of murdering off-duty soldier Lee Rigby, a 25-year-old Afghan war veteran in Woolwich, southeast London, in May last year.
Adebolajo received a whole-life term while Adebowale was told he would serve a minimum period of 45 years.
They were sentenced in their absence after being dragged shouting and struggling down to the cells by security guards with whom they had started brawling in the dock as Judge Nigel Sweeney opened his sentencing remarks.
"You decided, between you, and in order to advance your extremist cause, to murder a soldier in public in broad daylight and to do so in a way that would generate maximum media coverage," Sweeney told the Old Bailey court, calling the killing "barbaric."
"Sentence for murder is mandatory - it must be one of life imprisonment," he said.
The sentence was greeted with cheers by a large group of far-right demonstrators who had rigged up a mock gallows outside the court in central London.
The murder, which provoked a rise in hate crimes against Muslims in Britain and anti-Islamic street protests, made international headlines as a video of Adebolajo with blood-soaked hands standing in the street justifying the attack to nearby people travelled around the world.
Rigby's wife Rebecca told the court in a written statement that the death of the off-duty soldier, who had served in Afghanistan, Cyprus and Germany, was all the more shocking for having taken place in Britain.
"We both talked about the dangers of Afghanistan and we braced ourselves for it," said Rebecca Rigby. "You do not expect to see this on the streets of the United Kingdom.
"My son will grow up and see images of his dad that no son should have to endure and there's nothing I can do to change this," she said of their two-year-old child.
After the sentencing, Rigby's family issued a short statement saying: "We feel satisfied that justice has been served for Lee."
It was the first killing by Islamist militants in London since four suicide bombers killed 52 people in al Qaeda-inspired attacks on the transport network in July 2005.
Adebolajo and Adebowale, both of Nigerian descent and from Christian families, set upon Rigby with knives and a meat cleaver in what witnesses described as a "horrific frenzied attack" and "like a butcher attacking a joint of meat."
As Rigby lay dying in the road, several women tried to comfort him and even remonstrated with the killers, who had remained on the scene.
Judge Sweeney told the killers in his remarks: "Your sickening and pitiless conduct was in stark contrast to the compassion and bravery shown by the various women at the scene who tended to Lee Rigby's body and who challenged what you had done and said."
He called their extremist views a betrayal of Islam.
"You each converted to Islam some years ago. Thereafter you were radicalised and each became an extremist - espousing a cause and views which ... are a betrayal of Islam and of the peaceful Muslim communities who give so much to our country."
During the December trial, Adebolajo said: "I am a soldier of Allah. This is war."
In court on Wednesday, Adebolajo's defence lawyer had sought leniency from the judge as he said the pair targeted a soldier, rather than the wider public, did not use explosives and could possibly be rehabilitated.
But Sweeney said the two had carried out the murder to advancing a political, religious, racial or ideological cause.
He added, addressing the defendants: "... you butchered Lee Rigby - going, as you were well aware, far beyond what was needed to murder him. You, Adebolajo, concentrated on his neck - hacking at it repeatedly with first a substantial cleaver-type knife and then another knife, all in an attempt to decapitate him for maximum horrific effect.
"It is no exaggeration to say that what the two of you did resulted in a bloodbath."
(Editing by Mark Heinrich)