The government's chief information officer has said he expects the public sector to use commercial cloud-computing services as well as the 'G Cloud'.
John Suffolk said organisations will make use of generally available clouds, as well as the environment being designed specifically for the government.
The Cabinet Office is leading the development of the G Cloud to provide a shared, virtualised infrastructure for data storage and applications.
Speaking to journalists at the launch of Socitm's IT Trends 2009-10 report, he said the key factor will be what is most appropriate to the organisation's needs, and that 'public clouds' could in some cases offer a better deal.
"If it delivers good citizen outcomes at a price you can afford then use the public cloud," he said, adding that organisations will not be mandated to take any specific approach but will be left to make their own choices.
"We are saying to departments that they know their own business," he said. "We think it will flesh out a bigger strategic debate and will drive some towards the cloud, while others will take different approaches."
He qualified this, however, by saying that any personal data should not be kept on a public cloud, adding that when the G Cloud becomes available it will be a more appropriate repository for personal information.
Suffolk also suggested there is likely to be more than one cloud for public services, pointing out that healthcare bodies, the police and other organisations have different demands that would have to be satisfied.
He reiterated the rationale for the G Cloud as a model of reducing duplication and cutting costs for IT services to the public sector.
"You can't have hundreds of datacentres and tens or even hundreds of networks. You have to ask 'Do we need to do all this ourselves?' I just don't think it's a suitable model for the next 10 years."
An additional advantage would be that it would support small and medium-sized IT companies trying to win a share of the public-sector market.
"We see small, innovative organisations struggling to do business with the public sector because they can't show the scale that is necessary," Suffolk said, adding that they often need to provide an underlying infrastructure to applications or services. The G Cloud could provide the infrastructure on which they would work.
"We believe this will open up the market to SMEs because they don't have to bring the infrastructure. We want them to focus on top-end innovation delivering with outcomes for citizens, rather than bottom-end infrastructure."
Suffolk said more than 100 organisations are currently working on the G Cloud, addressing issues such as migrating data, security and the dangers of vendor lock-in. Suppliers have been encouraged to provide their knowledge of what has worked in a commercial environment in areas such as licensing.
A review of the work is expected to be published in mid-February. He declined to set a date when the G Cloud would be fully operational, suggesting it could be opened in increments. "We need to walk before we can run," he said.
