Primer: From BBC/
Iran has been blamed for a major cyber-attack on Parliamentary email accounts, including those of cabinet ministers.
Whitehall officials say Iran was behind a “sustained” cyber-attack on 23 June with hackers making repeated attempts to guess passwords of 9,000 accounts.
Up to 30 accounts are thought to have been compromised.
Security sources now believe the attackers came from Iran, although none of the information appears to have been used and the motive remains unclear.