A commissioning support unit (CSU) appears to be "in trouble" after losing the business of three of its local clinical commissioning groups (CCGs).
Dr Joe McGilligan, chair of Easy Surrey CCG (ESyDoc), expressed concern over the loss of CCG contracts the Surrey and Sussex CSU had suffered in recent months.
Surrey Downs CCG and Surrey Health CCG have chosen to work with Commissioning Support South CSU, while North West Surrey has defected to a London-based CSU.
Dr McGilligan said the loss of business has left the CSU "in trouble" and made it "difficult" for the organisation to present a viable offer to his CCG.
He confirmed ESyDoc CCG has also "expressed interest" in other CSUs' offerings but would like to sign with Surrey and Sussex CSU "to see if they can make a go of it".
Keith Douglas, managing director for Commissioning Support South CSU, denied he actively marketed his services to CCGs in Surrey.
"Both Surrey Downs and Surrey Heath approached us," he said.
"CSUs are in different places, we started earlier, which has allowed us to perhaps progress at a faster pace than others and have a proven track record.
"The CCGs were nervous about what was on offer [from Sussex and Surrey CSU] and came to us for stability and security."
Clodagh Warde-Robinson, managing director for Surrey and Sussex CSU, said she was "surprised" by Dr McGilligan's comments, considering ESyDoc CCG is one of the CSU's "key customers".
She said the claim the CSU was "in trouble" was "misleading" as the organisation is currently serving 12 CCGs with a population of 2.5m patients and 300 general practices.
"We absolutely have achieved critical mass as we are employing over 400 staff and have economies of scale. I am very confident we are creating a viable business," she said.
Warde-Robinson said there is a "shifting" of CCGs looking outside their area towards other CSU offerings happening all across the country and that it is not something that is "peculiar" to the Surrey and Sussex area.
Andrew Kenworthy, Director of CSU Transition Programme at the NHS Commissioning Board said: "CCGs have a choice as to where they source their support. It is important CCGs have confidence that their commissioning support arrangements will support them as they begin to take on their statutory duties."