Outgoing Information Commissioner Richard Thomas has renewed calls for greater funding and increased powers of inspection over public and private sector organisations.
"It is wholly unacceptable that the ICO should need the consent of a data controller to inspect its activities," he wrote.
"I welcome legislation currently before parliament to create the power to inspect public bodies. But this remains seriously deficient without a sanction for those who ignore the so-called requirements, and without extending our powers so we can also inspect the private sector."
Thomas also said that the watchdog's data protection budget, which is predicted to increase to around £16m thanks to the introduction of new tiered notification fees, is still not enough.
"This will remain tiny compared to other regulatory bodies," he said. "The ICO needs adequate and longer-term funding to enable us to fulfil properly all our complaint, guidance and enforcement responsibilities."
Thomas was replaced by Christopher Graham on 29 June.
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