...big bang projects - those with eye-watering price tags that take years to complete - to build and support bespoke systems, and Chant faces an uphill challenge to overturn this orthodoxy to fulfil the vision of the G-Cloud.
Chant is not blind to the scale of the task. "I think there will be lots of challenges on the way to this but there's nothing that I see that leads to something that means we can't do it," he told silicon.com.
Not least among these challenges is that many of those big bang IT programmes still have years left to play out - potentially tying government into the old model of IT service delivery for the foreseeable future. The complication of how to exit old deals would appear to be why government has been careful to specify "new" IT spend when talking about its ambitions to move to the cloud.
For evidence of how difficult it can be for government to extract itself from IT contracts there are few better examples than the £6.95bn NHS care records project. Key parts of the project are running years behind schedule but the government has been unable to pull out of the deal for fear of incurring penalty payments that could cost more than seeing the project through.
Sarah Burnett, head of public sector outsourcing research at analyst NelsonHall, said that it will be difficult for government to exit existing contracts, or transition them to a cloud service model.
"None of this is going to be particularly easy when it comes to existing contracts. Any kind of change and migration as a project is in progress is going to be quite hard: it's got to be managed and controlled and all the risks evaluated," she said.
For Mark Taylor, chief executive of SME Sirius and head of the New Suppliers to Government working group, the fact that government will be tied into contracts with existing vendors is evidenced by the small amount of money that it has to pledged to spend on cloud services.
The government expects the public sector to purchase some £60m of cloud services over the next six months under its first G-Cloud framework contract. This £60m, Taylor said, is less than one per cent of the £17bn to £20bn that government is estimated to spend on IT each year.
"Out of the what is spent on ICT each year it is only a fraction, less than a rounding error," he said.
"There is a huge inertia in the way that government is doing things and this seems to be the best kind of deal that can be done."
Offsetting Taylor's concerns over the government's low level of spending on cloud services is the fact that the initial G-cloud framework will only run for six months and will be followed by larger framework deals for government cloud services.
Chant admits that the year-long pause in the G-cloud programme following the 2010 election, while the coalition government assessed whether the project was worth going ahead with, probably led to instances where government bodies had "missed that opportunity" to switch to cloud services as contracts expired. However, not every existing IT contract will be allowed to run its course, he said.
"We will be reviewing the contracts. We may well find ourselves in the position where we need to exit from existing contracts and deal with the consequential costs of that because the benefits might be greater than staying in."
And while government is locked into a number of...