The Information Commissioner Elizabeth Denham has pointed out a gap in the government's white paper on online harms.
The head of the ICO said she was "surprised and disappointed" that there wasn't more focus on adverts using disinformation to influence elections, which she called "significant online harm".
The UK government released a long-awaited 'Online Harms' white paper earlier in April, which set out a regulatory framework for penalising tech companies and social media platforms that failed to tackle the spread of harmful and extremist content online.
But Denham, speaking to the Digital, Culture, Media and Sport (DCMS) Sub-Committee, pointed out a gap in the legislation which ignores the spread of disinformation used to influence political elections.
"I was surprised and disappointed that there wasn't more focus on what I think is a huge societal harm, which is around electoral interference and the need for more transparency in political advertising," she said to the DCMS sub-committee.
"It's surprising to me and concerning that the government hasn't done a comprehensive examination of political advertising and the oversight that's needed in this space."
The Sub-Committee on Disinformation was set up after the main committee completed its investigation into fake news online and the Cambridge Analytica scandal. MPs felt the issues raised needed further investigation.
The original committee laid out a series of recommendations for the government, which included the need for urgent legislative reform around the issues of online political advertising. The report concluded that misinformation from a range of sources threatened the UK's democracy.
However, some MPs on the sub-committee expressed concern that nothing had been done on the matter, especially considering the upcoming European Parliament elections, which are being held in May as a result of the UK's failure to finalise its plans to exit the EU.
On the subject of Brexit, one MP asked Denham whether she thought that the government's preoccupation with the issues around the UK leaving the EU had hindered progress on reforming political advertising.
She responded: "It's challenging and there is not enough legislative time to make improvements needed to protect our democratic processes."
Interestingly, Denham's office has been investigating adverts on social media sites during the 2016 EU referendum. Currently, the ICO is investigating ads run on Facebook by groups on both sides of the debate, including 1,000 placed by pro-Brexit group Mainstream Network, which spent more than 250,000 on its campaign.
According to Denham, those 1,000 ads had generated "around one million clicks".
The ICO is investigating what had happened to the data of those who had clicked on the ads, whom the ads had been placed by and how they had used Facebook's tools to target individuals.
"You can't leave it to an individual company," said Denham. "There needs to be more robust transparency tools and there needs to be regulation that requires companies to have systems in place to give real transparency.
"The world has moved quite quickly into digital campaigning and these campaigns run 365 days a year. And there are more ways than ever before to harvest data."
