Experts considered removing the Parsons Green Tube bomber from a list of extremists 10 days before he carried out the attack, a review has found.
Ahmed Hassan, 18, took a bomb onto the Tube last September after more than 18 months of concerns that he had been radicalised by the Islamic State group.
A review into how much police and other authorities knew of Hassan has been published on Monday.
It reveals a series of errors made by police and Surrey County Council.
