...large numbers of smaller vendors, according to the New Suppliers to Government working group's Taylor.
"Around one-third [of companies expressing interest in the contract] are SMEs, the rest are much bigger companies. Compare that to the number of SMEs in the country and it is a tiny fraction," he said.
Despite attempts by the government to simplify the process of becoming a supplier to the public sector, SMEs are still being put off by the need to fill out lengthy forms before government will consider them as a potential supplier for higher value contracts, Taylor said.
"In the private sector there is not a pre-tender questionnaire and a whole bunch of forms to get to the starting line," he said.
"That [the pre-tender documentation] has been greatly simplified moving forward, but the majority of SMEs still argue that it is too much trouble."
Has the government bitten off more than it can chew?
Even if government can overcome the contractual hurdles it could still struggle to meet the deadlines it has set itself on G-Cloud, as the government's ability to access cloud services in a secure and a reliable manner relies on it reforming its wider IT infrastructure.
"You have all these interdependencies between the different areas of the IT strategy and if one fails the other cannot be achieved," said Georgina O'Toole, director at analyst TechMarketView.
O'Toole gave the example of government's plan to have some 50 accredited cloud products and services available through the government app store by 2012. For this target to be met, she said, government will have to realise other goals to standardise end-user devices and implement common technical standards for networks.
"The end-user device strategy is very much intertwined with the push for open standards and the app store," she said.
NelsonHall's Burnett added: "There are a lot of interdependencies in the government's strategic implementation plan that is why I think the government's timescales might be a little ambitious. They have got their work cut out."
How much will be saved?
In this austerity-conscious era, government is loathe to do anything that won't save it money, and cloud does promise that.
When it comes to exactly how much will be saved from moving to the cloud the government is far more coy than it once was. In the early days of the project the then government CIO John Suffolk said that the G-Cloud programme was key to realising the £3.2bn annual savings targeted by government IT spend under the Operational Efficiency Programme.
Today Chant won't be drawn on the exact level of savings, preferring instead to provide examples of the type of cost reduction that has been achieved where government has made the leap to cloud.
The reduction in price will come from...