...using generic pay-as-you-go cloud systems, rather than bespoke, dedicated alternatives, and from high levels of competition to provide these cloud services, according to Chant.
The sheer size of the public sector and measures the government is putting in place to reduce the cost and time needed to apply for government contracts will encourage a diverse market of suppliers, he added.
"We've got enough scale to have a very vibrant market - take the example of we've probably got something like six million email accounts that we need in the public sector," he said.
"That's a lot of demand and what we can do is have a number of suppliers competing for that business.
"Once you've got that level of competition and we make sure we can get in and out of contracts and services easily, both from a technical and business integration point of view, we start to have a marketplace of commodity email services."
The first areas of work where government expects to utilise cloud services are in areas of commodity technology such as email, collaboration, CRM and infrastructure as a service. But Chant says that these applications are only the start, and that cloud technologies can be deployed and pieced together to build less immediately obviously applicable services, such as authentication and payment engines.
While moving away from bespoke IT systems may reduce the level of control that government has over the design of its software, improving that control can come at too high a price for an administration looking for savings. In a recent speech to an event hosted by the Institute for Government, Chant said that suppliers have charged government as much as £50,000 to change a single line of code in an application.
The move towards the cloud frees up government from costly overheads, according to the government's O'Neill, who gave the example of moving from an email system based on a local Microsoft Exchange server to the cloud-based Office 365 - which he said would immediately remove the hassle of administrating, managing and upgrading the email system from the organisation's hands.
"I go to Office 365, now most of that is no longer my problem," he said.
Giving an example of the scale of cost reduction that government could achieve, Chant said that email that handles data rated as restricted could be provided for about £1 per person per month using a public cloud package, compared to the up to £30 it costs at the moment.
The switch to the cloud will also play a central role in government plans to cut its datacentre running costs by 35 per cent over the next five years, allowing government datacentres to be shut down or reduced in size in favour of using more efficient datacentres run by cloud providers.
Whitehall has already begun saving money by switching to cloud, according to Chant, who said that the Government Digital Service (GDS), part of the Cabinet Office, has cut the running costs of its office systems by 80 per cent by moving to the Google Apps suite of email, calendar, contacts and word processing software - running on Apple Macs.
Chant said that Google Apps is suitable for use in the...