Blackmail concerns as 90 Westminster email accounts are hacked
As many as 90 email accounts have been compromised in a massive cyber attack on Westminster.
However, fewer than 1% of the system's 9,000 users were directly impacted by the "determined and sustained" attack.
It is not known if Northern Ireland's 18 MPs were affected by the security breach.
The incident gave rise to blackmail fears after hackers tried to break in to the accounts of MPs, peers and their staff by searching for weak passwords.
Investigations are under way to see whether any data has been lost. Officials said both Houses of Parliament will meet today as planned after staff worked to ensure business could continue in the wake of the hacking.
A parliamentary spokesman said: "Parliament's first priority has been to protect the parliamentary network and systems from the sustained and determined cyber attack to ensure that the business of the Houses can continue.
"This has been achieved and both Houses will meet as planned.
"Investigations are ongoing, but it has become clear that significantly fewer than 1% of the 9,000 accounts on the parliamentary network have been compromised as a result of the use of weak passwords that did not conform to guidance issued by the Parliamentary Digital Service.
"As they are identified, the individuals whose accounts have been compromised have been contacted and investigations to determine whether any data has been lost are underway," the spokesman added.
"Parliament is now putting in place plans to resume its wider IT services."
The National Cyber Security Centre (NCSC) and National Crime Agency are probing the incident, which came after reports that passwords for Cabinet ministers and MPs were being sold online by hackers.
North Down MP Lady Sylvia Hermon told the Belfast Telegraph that her email account had not been affected and put her cyber safety down to using complicated passwords.
"The head of the parliamentary digital service notified all MPs at lunchtime on Friday to say that they were investigating what was described as 'a cyber security incident'," she said.
"No other details were given apart from explaining that they were making some 'emergency changes to the IT network', which might cause some disruption.
"However, I've always used complicated passwords, which I regularly change, and so I was fairly confident a hacker couldn't access my emails.
"But, just to be sure, I phoned the parliamentary digital service today (Sunday) and have been reassured that I am not one of the MPs whose emails have been hacked. Thank goodness, I say, for a quirky password to access my emails.
"Apparently, only a very small number of MPs have been affected and they have been informed."
A parliamentary spokesman said MPs were informed of the problem via email on Friday and were sent two further updates.