The embattled chief executive of IT for the UK National Health Service's IT revamp sharply rebuked critics of the programme, saying a withdrawal of funding would lead to a "massive disruption" for patients.

Richard Granger, has led the National Programme for IT (NPfIT) for the last four and a half years, a £12.4 billion, 10-year programme that includes electronic prescription and appointment booking services, a patient care records service and an X-ray archiving and electronic transmission system, among other features.

"The programme gets continuously knocked," Granger said. "I don't think that will stop probably for another five years, and then the obituary on the programme will be 'Well why was it so difficult? Why didn't it get done more quickly?' and maybe the answer to that is: if there'd been a bit less whining and more support, it might have done."

Granger left immediately after his keynote speech at a healthcare and government procurement trade show yesterday and did not address the latest crisis involving an NPfIT subcontractor, iSoft. The company is charged with delivering a patient care records service for lead contractor, CSC responsible for three out of five geographic areas for the project.

iSoft, which has run into accounting and management problems, recently reached a buyout deal with the Australian software firm IBA. But CSC blocked the deal while it works out with iSoft how the patient care records system will be delivered.

The two companies remain in discussions, but the conflict reinforced concerns about the ability of suppliers to deliver products and meet deadlines. Some of the more extreme critics of the programme have called for a withdrawal of funding.

In general, Granger acknowledged deployment problems, in part because each hospital conducts operations differently and requires different IT configurations.

Granger also said there have been problems integrating the 10,000 or so pharmacies with the Electronic Prescription Service (EPS), which uses an XML (Extensible Markup Language) format, HL7. So far, 17 or 18 different systems are used within the pharmacies to accept prescription messages from the heath-care system's core network.

Work on the EPS has been slow and resistance to change has been high, Granger said.

"We have found it interesting how appalling and how slow some of the big corporates, FTSE 100 corporates, have been at getting their software to be HL7 message compliant," Granger said. "I might almost imagine they are not welcoming with open arms the challenge to their bricks-and-mortar business model."

But he cited statistics that indicate there has been some success. During his presentation, Granger said there were 2,250 appointments booked using electronic systems and 17,250 prescriptions transmitted electronically, 168,950 digital images related to patient care recorded and 37,500 secure emails sent containing patient clinical data.