Facebook is delaying its plans to require British political advertisers to verify their identity, the Guardian can reveal, after a spate of failures on the part of the company to vet disclosers in the UK and US.

The social network will bring in the requirement “in the next month”, it says, pushing back the initial deadline of Wednesday 7 November.

“We have learnt that some people may try to game the disclaimer system by entering inaccurate details and have been working to improve our review process to detect and prevent this kind of abuse,” a Facebook spokesperson said in a statement.

“Once we have strengthened our process for ensuring the accuracy of disclaimers, we will be introducing enforcement systems to identify political advertisers and require them to go through the authorisation process.”

Facebook launched the first phase of its UK political advertising transparency effort in October, allowing political advertisers to register to prove their location, and creating a voluntary system whereby they could disclose who had paid for particular adverts, and add them to an Ad Library where they would be archived for seven years.

The company had initially planned to make the system compulsory by 7 November, but in the intervening time, a damaging series of stories cast doubts on the effectiveness of the project.

Facebook’s founder and CEO, Mark Zuckerberg. Photograph: Charles Platiau/Reuters

In the US, Vice News used the system to “disclose” that adverts were paid for by every single US senator, vice-president Mike Pence, and Islamic State. Facebook approved every disclosure, and the adverts entered the archive intact.

In the UK, Business Insider similarly “disclosed” that adverts attacking Brexit were paid for by Cambridge Analytica, the now-defunct political consultancy whose acquisition of the personal data of more than 100 million Facebook users sparked a scandal earlier this year.

The investigative journalism organisation ProPublica highlighted one real-world consequence of the policy: a series of pro-Trump adverts that were attributed to “Energy4US” on the social network, a company that has no offline existence. In fact, ProPublica discovered, Energy4US “appears to be a front for American Fuel & Petrochemical Manufacturers, a trade association whose members include ExxonMobil, BP, Chevron and Shell”.

Facebook said: “Since we announced our political ads authorisation and Ad Library in October we have seen hundreds of people go through the authorisation process. Authorised advertisers create a ‘paid for by’ disclaimer as part of this process and we require them to represent themselves accurately when they fill this in.”

Other social networks take a different approach. Twitter, for instance, also requires American political advertisers to disclose who paid for adverts, but requires that disclosure to be linked to an employer record, limiting the ability of potentially malicious actors to create fictional identities.

Facebook declined to set a new date for the final stage of its UK rollout of the ad transparency rules, telling the Guardian: “We will continue to roll out and refine these systems out over the next month so that we have a higher level of protection in place before next May’s local elections.”