The Information Commissioner's Office (ICO) is to take action against websites that fail to comply with EU regulations concerning the use of cookies.
Dave Evans, business and industry group manager at the ICO, said the data protection watchdog had written to 75 of the most visited websites, asking what steps they had taken to achieve compliance.
However, some have not responded to its enquiries, prompting the organisation to act.
"Some sites have failed to engage with us at all, and they're now being set a deadline to take steps towards compliance, with formal enforcement action likely if they fail to meet this deadline," said Evans.
Companies that do not respond to the enforcement notice could face criminal charges.
The cookie guidance is one area of the law where he has seen most progress, in terms of making businesses aware of the new regulations, said Evans. Although, there is still more work to be done.
"It might be a law they wish didn't exist, but the simple fact is that it is here to stay. The EU passed the legislation, the Department for Culture, Media and Sport (DCMS) implemented it, and it's now the ICO's job to regulate the organisations that have to comply," he said.
He said the ICO is learning more about what consumers care about. "We've had more than 380 responses to our online cookie concern reporting tool so far,' said Evans.
The ICO is responding to those concerns, with a progress report due to be published on its website in November.
Evans remarks follow an IT Pro report about web development company SilkTide, who urged the ICO to take action against it for deliberately defying the EU cookie law.
Silktide described the new law, which came into force in May this year, as a "stupefying waste of time".
