An urgent review of Westminster security is under way after Prime Minister Tony Blair was hit by a purple flour bomb during Commons question time.
Pressure group Fathers 4 Justice said one of its members had thrown the missile from the public gallery, which splattered the dyed flour across the back of Mr Blair's jacket as he stood at the Despatch Box.
The incident sparked a huge Commons inquest with claims that Speaker Michael Martin had breached security protocol by immediately clearing the chamber, instead of sealing it in case the powder had been poisonous.
Mr Blair was shepherded to his private office behind the chamber and his jacket was taken away for examination, as MPs poured out of the Commons - potentially spreading any infectious agent.
The premier was said to be anxious to resume Prime Minister's Question Time as soon as the all-clear had been given, but after the Commons had been suspended for 70 minutes he accepted that was not possible.
Mr Martin told MPs that the House authorities would now review the way the incident was handled "to ensure all appropriate procedures are followed if necessary in the future".
Commons leader Mr Peter Hain said: "A thorough review of security is taking place with the Security Service and the Metropolitan Police. It must now take account of the full circumstances of today's incident. It has caused deep concern to Members of the House, staff and visitors."
PA