Thousands of inactive accounts will be deleted next month unless they log in before December 11, Twitter has announced.
'Inactive' accounts refer to those not used in the past six months, with the social media giant confirming the cull will include accounts belonging to people who have died.
The move is to free up usernames, according to the site.
Concerns have been raised by Brendan Cox, husband of the murdered Batley & Spen MP, who has contacted Twitter asking for help in preserving her account as it contains pictures and memories.
In a tweet directed to the company on Wednesday, Mr Cox wrote: "Slightly worried Twitter might delete @Jo_Cox1 account in their clean up of dormant accounts.
"Can anyone advise on how to stop this. There’s lots on there we want to keep as a family."
A spokesman for the social media platform said: "As part of our commitment to serve the public conversation, we're working to clean up inactive accounts to present more accurate, credible information people can trust across Twitter.
"Part of this effort is encouraging people to actively log in and use Twitter when they register an account, as stated in our Inactive Accounts Policy.
"We have begun proactive outreach to many accounts who have not logged into Twitter in over six months to inform them that their accounts may be permanently removed due to prolonged inactivity."
An email was sent to the users of inactive users on Tuesday urging them to log in before December 11 to avoid deletion.
Twitter currently allows family of people who have passed away to request their accounts are deactivated on proof of ID and death, but does not grant them access which relatives would need to obtain to avoid deletion.