'Brute force' cyber attack on Parliament compromised up to 90 email accounts

A cyber attack on Parliament compromised almost 100 email accounts, sources have said.

An unprecedented attack by hackers seeking to break into MPs’ inboxes utilising a “brute force” assault which lasted for more than 12 hours on Friday prompted fears that senior politicians could become the targets of blackmail.

But the “determined and sustained” offensive is now believed to have only compromised up to 90 email accounts with less than one per cent of Parliament’s 9,000 users directly impacted.

Unknown hackers repeatedly probed "weak" passwords of politicians and aides, forcing parliamentary officials to lock MPs out of their own email accounts as they scrambled to minimise the damage from the incident.

The network affected is used by every MP including Theresa May, the Prime Minister, and her cabinet ministers for dealing with constituents.

Experts warned that politicians could be exposed to blackmail or face a heightened threat of terrorist attack if emails were accessed.

MPs also apologised to constituents and expressed concerns that sensitive and private information shared with them may have leaked.