A BBC Undercover Voters project uncovered widespread sharing of videos with false information, manipulated footage often involving party leaders, and abusive content and comments.
TikTok has become a significant platform, having grown substantially since the 2019 election. Ofcom reports it as a key news source for both adults and teenagers. Labour and the Conservatives have heavily invested in Facebook and Instagram advertising (both owned by Meta), with Labour spending five times more than the Conservatives on YouTube ads by the end of May.
The investigation found some videos with hundreds of thousands of views, including one spreading a rumour that a major scandal prompted Rishi Sunak to call an election and the repeatedly discredited accusation that Sir Keir Starmer was responsible for the state's failure to prosecute Jimmy Saville for his serial sex crimes.
Another video falsely claimed that under the Conservatives' proposed National Service plan, 18-year-olds would be sent to fight in Ukraine and Gaza.
The content is shared by genuine users who may believe it's true and by political activists and anonymous bot accounts.
The Undercover Voters project created 24 fictional profiles on social media, based on data from the National Centre for Social Research, representing voters in key constituencies across the UK.
BBC's disinformation reporter and social media correspondent Marianna Spring noticed more comments supporting Reform UK than any other party and attempted to contact the posters. Some were real individuals without ties to Reform UK, while others appeared to be bot accounts.
The investigation highlighted the challenge of regulating such content, especially when distinguishing between parody and reality, which is difficult in the current political climate.
While some parody and satire videos are clearly labelled, the investigation revealed that some TikTok users are confused about which claims are valid and which are parodies.
A 16-year-old girl, not affiliated with any party, made a parody video about Rishi Sunak's TikTok on national service "for a joke." It received over 400,000 views, and although she acknowledged it could mislead people, she hoped viewers would recognise it as just fun.
While it is ok and natural for teenagers to take the Nintendo of politicians, the BBC investigation raises concerns, particularly when it comes to convincing deepfakes of politicians.
A TikTok spokesperson told the BBC that the company has increased its investment to ensure trustworthy information is available on TikTok, launching a "UK Election Centre with a fact-checking expert" and implementing "industry-leading AI labelling technology."
TikTok also mentioned introducing "more policies to counteract foreign election interference" and stated that it removed 97 per cent of videos with the election and civic misinformation before they were viewed.