"In particular, we believe that the updated policy does not provide sufficient information to enable UK users of Google's services to understand how their data will be used across all of the company's products," the watchdog said.
The ICO's enforcement powers range from simply issuing orders, known as "undertakings", to force organisations to improve their data protection compliance, all the way up to fines of £500,000 for serious breaches of the Data Protection Act.
However, users are unable to opt out of the new policies if they wish to continue using Google products, and critics said it could results in a loss of online privacy.
However, the company did not say whether it was planning to change its policy before the deadline.
Google has been fighting a number of privacy battles recently. Last month the ICO told the search giant it must delete all Wi-Fi payload data collected by its Street View cars in the UK, while its Google Glass experimental wearable computing device is also causing some privacy concerns.