Deputy Information Commissioner David Smith criticized Google at a conference in Westminster.
"Being vague does not help in giving users effective control about how their information is shared. It's their information at the end of the day," he added.
His comments echo those of the French privacy watchdog, CNIL, which had called on Google to delay the unveiling of new policy.
European Commissioner Viviane Reding had earlier accused the firm of "sneaking away" citizens' privacy and warned that "we aren't playing games here".
The new policy gives Google powers to pool personal information from search Gmail Maps, YouTube and dozens of other services to create a single profile of a user's interests to target advertising. (ANI)