The British government has determined that BlackBerry's new devices are not secure enough for sensitive work, The Guardian reports. Though BlackBerry's pedigree shows a focus on enterprise security, its upcoming Z10 and Q10 smartphones didn't receive clearance from the UK's Communications Electronic Security Group. The decision comes despite BlackBerry's efforts to add new security measures, including Balance: a feature that secures work documents separately from the rest of the device. BlackBerry is working with the CESG to have its devices approved, but it's unclear when software updates will come to address the security concerns.

As the launch of BlackBerry's new operating system approaches, the company has been trying to reiterate its position as a secure solution for government and corporate users. Its previous operating system, BlackBerry OS 7.1, received approval by both the US and UK governments for varying levels of restricted data, The Guardian notes. Other manufacturers' devices, including some of Apple's iPhones, have received select clearances from the CESG. The Z10 has been available in the UK since January, and will go on sale in the United States before the end of March — but whether the security features will be enough to recapture enterprise users remains to be seen.

Update: BlackBerry has provided us with a statement in response, which we've reproduced below. The company says that BlackBerry 10's failure to meet CESG standards is down to a change in the approval process, but doesn't give a timeframe for when the new OS might get the go-ahead.

We have a long-established relationship with CESG and we remain the only mobile solution approved for use at 'Restricted' when configured in accordance with CESG guidelines. This level of approval only comes following a process which is rigorous and absolutely necessary given the highly confidential nature of the communications being transmitted. The current re-structuring of this approval process, due to the Government Protective Marking Scheme review and the new CESG Commercial Product Assurance scheme has an impact on the timeline for BlackBerry 10 to receive a similar level of approval. The U.S. government's FIPS 140-2 certification of BlackBerry 10 and the selection of BlackBerry 10 by the German Procurement Office and Federal Office for Information Security (BSI) underline how our new platform continues to set the standard for government communications. We are continuing to work closely with CESG on the approval of BlackBerry 10 and we're confident that BlackBerry 10 will only strengthen our position as the mobile solution of choice for the U.K. government.

Update 2: In a bizarre new turn, the UK government has issued a statement saying that it hasn't yet evaluated the security of the BlackBerry 10 platform, and The Guardian has pulled its original story. CESG notes that it's had a "long-standing security partnership with BlackBerry" and that it's confident BlackBerry 10 will likely "represent a viable solution for the UK Government. The full statement can be found below.