The warning comes after the Department for Culture, Media and Sport (DCMS) admitted that guidelines on what businesses must do to comply with the new directive will not be ready before the 25 May enforcement date.
The directive will require businesses to obtain explicit consent from web users who are being tracked using text files commonly known as "cookies".
The directive also requires that businesses inform website users about the information being stored in cookies and how that is used to determine which adverts they see.
In a statement, culture minister Ed Vaizey said he recognised that the delay would cause uncertainty for businesses and consumers.
Businesses should not consider the delay as "a get out of jail free card," he said, as the new privacy directive is law and will be enforced in the UK.
This story was first published by Computer Weekly