Twitter has shut off access to 31 accounts that chronicled and archived the deleted tweets of politicians, diplomats and embassies around the world.
The move follows the social network’s earlier blocking of Politwoops US, which archived deleted tweets by American lawmakers.
Several MPs were caught out, including several Tory MPs who deleted old tweets which boasted of the UK’s AAA credit rating – after it lost it in February 2013.
Former Lib Dem MP Danny Alexander was also caught deleting positive polling tweets when it became clear he was about to be ousted by the SNP at May’s election.
But Twitter says the idea of messages being effectively impossible to delete is “terrifying”, and has now blocked the account’s automated access to Twitter’s data.
Twitter said the decision followed “thoughtful internal deliberation”, adding: “Imagine how nerve-racking – terrifying, even – tweeting would be if it was immutable and irrevocable?
“No one user is more deserving of that ability than another. Indeed, deleting a tweet is an expression of the user’s voice.”
Another 30 Politwoops-linked accounts around the world, and overseen by the Open State Foundation, have also been cut off from the service.
But the foundation’s director, Arjan El Fassed, said: “What elected politicians publicly say is a matter of public record. Even when tweets are deleted, it’s part of parliamentary history. These tweets were once posted and later deleted.
“What politicians say in public should be available to anyone. This is not about typos but it is a unique insight on how messages from elected politicians can change without notice.”
Jules Mattsson, who runs the UK account, told The Guardian: “Politicians are all too happy to use social media to campaign but if we lose the ability for this to be properly preserved, it becomes a one way tool.
“Social media is playing an increasing role in British politics and this denies us an opportunity to extend proper accountability to social platforms.”