According to The Times, the stolen data revealed the private login details of 1,000 British members of Parliament and parliamentary staff, 7,000 police employees and more than 1,000 Foreign Office officials.

The National Cyber Security Center, which was set up to protect the country against cyberattacks, said that it would reissue guidance to government departments after being presented with the findings.

The parliamentary authorities are also working with the center to protect the network and ascertain the scale of the damage, according to a spokeswoman for the House of Commons, who did not provide a name by British convention.

In a statement, the spokeswoman said that “the Houses of Parliament have discovered unauthorized attempts to access parliamentary user accounts. We are continuing to investigate this incident and take further measures to secure the computer network, liaising with the National Cyber Security Center.”

To protect member and staff accounts and “secure our network,” the statement added, “we have temporarily restricted remote access to the network. As a result, some members of Parliament and staff cannot access their email accounts outside of Westminster.”