Labour Party Loses Control of Member Data in Major ‘Cyber Incident’

Cyber-security authorities have warned that the possible hacking attack has potentially compromised the personal information of Labour Party members and registered supporters, who number almost half a million people.

The Labour Party says it has lost access to the data of some 430,000 members in a mysterious "cyber incident".

The cyber attack on a third party firm that manages Labour's databases occurred on Friday, October 29, and the party was informed the same day, but only announced the problem on Wednesday.

A party spokesman said that a "significant quantity of Party data" was "rendered inaccessible on their systems."

The data included "information provided to the Party by its members, registered and affiliated supporters, and other individuals who have provided their information to the Party."

Labour has an estimated 430,000 individuals on its books. Just over half are individual members who pay fees directly, a quarter are members through an affiliated trade union and a fifth are reportedly "registered supporters" with limited voting rights under a system introduced by former leader Ed Miliband.

Labour said the data breach was "immediately reported to the relevant authorities, including the National Crime Agency (NCA), National Cyber Security Centre (NCSC) and the Information Commissioner’s Office (ICO)," while experts were brought in to assist in the investigation.

"The Party is also working closely and on an urgent basis with the third party in order to understand the full nature, circumstances and impact of the incident," the spokesman said, adding: "The Party’s own data systems were unaffected by this incident."

The NCA said it was "leading the criminal investigation" and "working closely with partners to mitigate any potential risk and assess the nature of this incident."

The NCSC said it was also investigating and trying to mitigate the impact on those members whose data may have been stolen.

"We would urge anyone who thinks they may have been the victim of a data breach to be especially vigilant against suspicious emails, phone calls or text messages and to follow the steps set out in our data breaches guidance," an NCSC spokesman said.

Labour's membership has slumped by around 170,000 from a high of 600,000 under former leader Jeremy Corbyn, mostly since his replacement by Sir Keir Starmer.

In July the party announced some 90 redundancies at its head office in Victoria Street, Westminster, due to a combination of falling membership and £2 million in legal fees and compensation pay-outs linked to a leaked report into unsubstantiated claims of anti-Semitism.