The government has rubber-stamped the use of the controversial Phorm ad-serving technology, claiming that the system will not break EU data protection laws as long as users are given a choice and are able easily to opt-out.

In July, European Commissioner Viviane Reding demanded more information on the technology, which tracks user behaviour in order to target ads more effectively.

After being granted an extension to the original August deadline, the Department for Business, Enterprise & Regulatory Reform has finally sent its response.

The department will not publicly release the full statement, but in the small part of the letter that has been made public it states that "Phorm's products are capable of being operated" as long as they comply with various requirements.

These include that "user profiling occurs with the knowledge and agreement of the customer" and that "Phorm does not keep a record of actual sites visited".

"Users will be presented with an unavoidable statement about the product and asked to exercise a choice about whether to be involved," the statement adds.

"Users will be able to easily access information on how to change their mind at any point and are free to opt in or out of the scheme."

Questions about Phorm's legality first surfaced when it emerged that firms including BT were trailing the technology without informing users.