A group of leading computing academics has written a new open letter to MPs calling for an immediate inquiry into the NHS's £12.4bn National Programme for IT (NPfIT).
The academics say a report on the programme in June by the National Audit Office did not answer any of their concerns.
They are increasingly worried that the systems being built may not work adequately - and that even if they do work they may not meet the needs of many NHS trusts.
In a new open letter to Kevin Barron, chairman of the House of Commons' Health Committee, the group says its members strongly believe that an independent technical review is an essential first step in helping the project to succeed.
The letter says: "As a review will take several months to organise, conduct and report, we believe there is a compelling case for your committee to conduct an immediate inquiry to establish the scale of the risks facing the NPfIT."
The group also wants the committee to help "identify appropriate shorter-term measures to protect the programme's objectives".
Plans for the NPfIT include systems to allow summary electronic medical records on 50 million patients to be shared, and also systems to enable hospital appointments to be booked online.
Since the group's first open letter to the Health Committee in April, Accenture has announced it is withdrawing from its original £2bn NPfIT deal. The main software supplier to the programme, Isoft, has reported losses of £383m, and the Financial Services Authority has launched an investigation into the company.
The chairman of the British Computer Society's Health Informatics Forum, Glyn Hayes, has questioned whether a centralised approach will work within the complex organisational structure of the NHS, and Computer Weekly has reported that some NHS trusts have been hit by more than 110 major incidents in four months.Click for text of the open letter, plus news analysis