The UK Parliament has been hit by a cyber-security attack.
MPs were reportedly told about the hack on Friday night and later told of difficulties in accessing their emails away from the Westminster estate.
A Commons spokeswoman said the lack of email access was not a result of the cyber-attack itself but part of the steps being taken to manage the issue.
She said Parliamentary authorities were liaising with the National Cyber Security Centre.
The spokeswoman said: “The Houses of Parliament have discovered unauthorised attempts to access parliamentary user accounts.
“We are continuing to investigate this incident and take further measures to secure the computer network..
‘Disabled remote access’
“We have systems in place to protect member and staff accounts and are taking the necessary steps to protect our systems.”
She added: “Parliament has disabled remote access to protect the network.”
A number of MPs have confirmed to the BBC they are not able to access their parliamentary email accounts remotely.
The attack was publicly revealed by Liberal Democrat peer Lord Rennard on Twitter who had also asked his followers to send any “urgent messages” to him by text.
The incident comes just over a month since 48 of England’s NHS trusts were hit by a cyber-attack.
The government’s National Security Strategy said in 2015 that the threat from cyber attacks was one of the “most significant risks to UK interests”.
The National Cyber Security Centre, which is part of intelligence agency GCHQ, started its operations in October last year.