A man has today appeared at Peterborough Crown Court and pleaded guilty to attempted murder.
Kevin McCarthy, 49, of HMP Whitemoor, appeared at court this morning via video link.
He is due to be sentence at Peterborough Crown Court tomorrow.
The incident happened at the prison in October, 2016.
The victim, Damien Fowkes, 41, of HMP Whitemoor was taken to hospital where he was treated for life threatening injuries to his neck.
Fowkes was jailed for a minimum of 20 years in 2011 for attempting to murder Soham murderer Ian Huntley and for the manslaughter of child killer Colin Hatch.
He was also serving a sentence for armed robbery.