Critics are convinced that some suppliers could "skip" G-Cloud 7 as the standstill period ahead of its launch begins.
The seventh iteration of the framework, which recently broke through the £800m barrier in terms of revenue transacted, is set to go live on 23 November, with intention-to-award notifications set to go out earlier this week.
But critics claim the addition of a new clause that will make it harder for clients to scale up the services they buy - in the form of a 20 per cent cap - may lead to it being bypassed by swathes of suppliers.
G-Cloud supplier Eduserve and supplier body EuroCloud are among those to have issued statements criticising the cap, which they say flies in the face of the very concept behind the pay-as-you-grow cloud model.
Talking to CRN, EuroCloud UK chair Phil Wainwright, said suppliers had to accept they were "stuck with it, at least until G-Cloud 8".
"Some suppliers are not going to use it and will use G-Cloud 6 instead," he said.
"You've always got two that work in parallel so you can skip a generation, in the same way people skip a generation of Microsoft Windows."
Mike Hayward, EMEA head of public sector at Huddle, a SaaS-based collaboration provider that has won over 200 deals through G-Cloud, said the "barrier" the cap would introduce may force some public sector buyers to seek alternative routes for cloud purchases.
"The nature of SaaS and cloud is people start small. They do a full-blown selection procedure to get the best supplier, and once they've done that don't want to go through that whole exercise again," he said.
"If the overheads become onerous and repetitive, for no good cause, I think people would start to look at other routes, which as a G-Cloud supplier we wouldn't want to see."
Wainwright said he had heard the cap defended on the basis that it reflects EU procurement rules stipulating a 50 per cent cap on any public procurement.
"But that doesn't explain why it's a 20 per cent cap," he said. "Also, the whole point of G-Cloud is to provide a way to avoid some of the traditional European public procurement rules that didn't work in a cloud context, and this cap is another example of those kinds of rules."
Details of the cap are contained in documentation applicants downloaded to participate in the tender, according to Wainwright.
"There was very little opportunity for people to give feedback and we are asking for more dialogue," he said.
Hayward did, however, praise changes in the submissions process he said made it "far easier" for suppliers to submit listing into the frameworks.
"That is a big improvement," he said.
Infrastructure provider says international sales now make up 51 per cent of its revenue
Suzanne Chappell of TMS plans sailing venture after selling Oxfordshire-based TMS to acquisitive Chess
Withdrawal of credit insurance by some providers a 'reflection' of current challenge facing IT sector, according to MD Steve Soper
SMART's UK managing director joins Lenovo to boost SMB business