The father of Fusilier Lee Rigby has said he wants an apology from Britain's intelligence services after accusing them of failing to prevent his son's murder.
The Intelligence and Security Committee said in a report that spy agencies could not have stopped the soldier's murder in May 2013, despite his killers featuring in a total of seven error-filled operations before the attack.
Prime Minister David Cameron has said lessons can be learned from a report into actions taken by intelligence agencies in the lead up to soldier Lee Rigby's murder.
Mr Cameron said: "There are lessons to be learned and things that need to change."
The report, by the Intelligence and Security Committee, concluded intelligence agencies could not have prevented the murder of Rigby despite his killers featuring in a total of seven error-filled operations before the attack.
Lee Rigby's stepdad and sister criticised social media companies for failing to notify the authorities of users plotting a terror attack.
ITV's UK Editor Rohit Kachroo looks at the findings of a report into the extent of intelligence agencies' knowledge of Lee Rigby's killers