The fanatics who murdered soldier Lee Rigby have brought chaos to a courtroom at London's Old Bailey as one of the killers was condemned to die behind bars.

Heartbroken relatives of the 25-year-old Fusilier said justice has been served after Michael Adebolajo was given a whole life term for the barbaric killing. His accomplice Michael Adebowale was sentenced to life with a minimum term of 45 years.

In an emotional victim impact statement, the soldier's widow Rebecca said: "Of all the feelings I have, the one thing that overrides everything is that I know my son will grow up and see images of his dad that no son should ever have to endure, and there is nothing I can do to change this."

Dressed in Islamic robes, the British-born extremists erupted with rage as Mr Justice Sweeney said they had been radicalised and had betrayed their religion.

The judge was forced to sentence the "sickening and pitiless" killers in their absence for butchering the father of one in broad daylight near Woolwich barracks on May 22 last year.

As Mr Justice Sweeney began his sentencing remarks, the pair disrupted proceeding, forcing the judge to stop speaking. Adebolajo, 29, screamed "Allahu akbar" as he and Adebowale, 22, were pinned to the ground and bundled down to the cells by several prison officers following their outbursts.

The judge had told them: "You each converted to Islam some years ago. Thereafter you were radicalised and each became an extremist, espousing a cause and views which, as has been said elsewhere, are a betrayal of Islam and of the peaceful Muslim communities who give so much to our country."

In response, Adebowale had declared "that's a lie" and "it's not a betrayal of Islam" and ranted about Britain and America.

After the killers were removed, Mr Justice Sweeney continued: "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, including getting yourselves killed by armed officers who would be bound to attend the scene in the aftermath of the murder, thereby expecting you would become martyrs and gain a place in paradise."

Adebolajo and Adebowale targeted the young soldier because he was wearing a Help for Heroes top. They mowed him down in a car before hacking at his limp body with a meat cleaver and knives in an attempt to decapitate him.

Mr Justice Sweeney said: "You both exited the car armed with knives and over a period of around two to three minutes you butchered Lee Rigby; going, as you were well aware, far beyond what was needed to murder him."

Explaining his decision to give Adebolajo a whole life term, he said the killer, who has two children and four stepchildren, was the leader of the plot and had "no real prospect of rehabilitation".

Adebowale's younger age, mental health problems and lesser role meant he escaped spending the rest of his natural life behind bars.

Relatives of the soldier including his widow, his fiancee Aimee West, mother Lyn and stepfather Ian were all in court as the pair were jailed. Some had arrived at the Old Bailey with T-shirts adorned with images of Fusilier Rigby.

Following the dramatic scenes, a police family liaison officer read a statement on the family's behalf. It said: "We would like to thank the judge and the courts for handing down what we believe to be the right prison terms.

"It has brought us a lot of comfort and we feel satisfied that justice has been served for Lee."

Outside the court far-right protesters had erected two sets of mock gallows, and waved flags and chanted in the background.

The war veteran's stepfather, Ian Rigby, said: "After all he had been through in Afghanistan, all Lee was doing was just walking through London. Just seeing on the TV and seeing the violence of it you just can't comprehend. You take it all in and it doesn't click in your head."

Home Secretary Theresa May said: "Extremist behaviour will never be tolerated in Britain. While nothing can reverse the appalling crime committed last May, the significant sentences handed down today reflect this."