On 24 June we discovered unauthorised attempts to access accounts of parliamentary networks users and are investigating this ongoing incident, working closely with the National Cyber Security Centre.
Parliament has robust measures in place to protect all of our accounts and systems.
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 today.
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 under way.
Parliament is now putting in place plans to resume its wider IT services.
We'll continue to update Members of both Houses of Parliament and the public.
Updated 11am, 26 June 2017