People in Hackney are being urged to reapply for their postal vote as the cyber-attack continues to disrupt the council's systems.
After organised criminals targeted Hackney Council last October, the authority has grappled with a range of issues with its services, such as making and taking payments.
The council today (January 21) reassured residents none of the "limited set" of stolen data published on the dark web this month relates to postal voting.
However, it is asking all existing postal voters to resubmit an application form so their votes can be verified in elections.
Upcoming elections include those scheduled for May 6, to decide the next mayor of London and London Assembly members, and by-elections in Stamford Hill West, Kings Park, Hoxton East and Shoreditch, and Woodberry Down wards.
Affected people will still be able to vote in person at a polling station.
The council is, however, encouraging everyone to register as a postal voter to better allow for social distancing in light of the Covid-19 pandemic.
Tim Shields, returning officer and chief executive of Hackney Council, said: “I’m really sorry for the additional disruption that this attack by organised criminals is continuing to cause residents – and I share their anger and frustration.
"I know that many people may be concerned about their personal data, but there is no evidence to suggest that their postal vote registration data has been stolen or published online.
"Due to coronavirus, voting will be different this year, and we are encouraging as many people as possible to register to vote by post to reduce pressure on polling stations and the social distancing we will need to follow to help keep everyone safe.”
Around 100 registered postal voters who have a signature waiver – for reasons such as disability – are not affected and do not need to reapply.
The council has recovered its election system onto a cloud-based platform and is working with the National Cyber Security Centre and other cybersecurity experts to make sure it is secure.
Residents can apply for a postal vote by using a prepaid envelope to return the form, if they have received one from the council, or by downloading it and returning it by post or email.
READ MORE: Hackney Council cyber-attack: Stolen data published on the dark web
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