The revamp of NHS IT has been fraught with problems
The introduction of computerised NHS patient records in England could be hit by more delays, MPs warn.
The Committee on Public Accounts has thrown fresh doubt on a 2015 deadline for the ambitious £12bn project.
Its chairman said that even in trusts already using parts of the system, staff were unimpressed and the cost to the NHS was uncertain.
The government said new IT systems in the NHS were delivering "better, safer and faster care".
The NHS Programme for IT in England, which aims to allow information about patients to be shared securely between hospitals and GP practices, has been dogged by problems since its launch in 2002.
The project was originally intended to be completed by next year, but its complexity has delayed this by up to five years.
Two out of the four companies producing the system for the NHS have pulled out, and some hospitals have been forced to bring in their own new "interim" electronic software to replace existing ageing systems which could not keep pace with policy innovations such as "Choose and Book", and 18-week targets.
Edward Leigh MP, the committee's chairman, said that the risks to the successful deployment of the system were "as serious as ever".
While some systems were in place, he said, the "Care Records System" - at the heart of the project - was "way off the pace".
"Even the revised completion date of 2014-2015 for these systems now looks doubtful in the light of the termination last year of Fujitsu's contract covering the South."
Not a single trust in the North, Midlands and East had begun using care records software as of the end of last year, he said.
"Essential systems are late, or, when deployed, do not meet expectations of clinical staff, estimates of local costs are still very unreliable, and, despite action to secure their commitment, many NHS staff remain unenthusiastic."
Trusts can still decide not to use the care records systems they are offered, but the taxpayer could still be forced to pay for their development, he said.
However, he said that the Department of Health should consider making money available to help trusts pay for alternatives if there was no improvement within six months.
A spokesman for the Department said it welcomed the report, saying that the delays in implementation had cut the cost burden on the NHS.
Most of the delay had been caused by the need to add extra functions, he added.
"New IT systems in the NHS are delivering better, safer and faster care.
"Costs are also controlled by the contracts which only pay to providers once the service has been successfully delivered."
Dr Vivienne Nathanson, Head of Science and Ethics at the British Medical Association said: “With the UK deep in recession the government must ensure that Connecting for Health confronts the lessons of the past - the NHS IT project can't be paid for with a blank cheque.
"Despite the problems we must not lose sight of the potential benefits that could be delivered in terms of patient safety, by the National Programme for IT."
Nigel Edwards, policy director of the NHS Confederation which represents 95% of NHS organisations said: "NHS organisations have already had to work around the delays by putting alternative IT systems in place.
"Everyone recognises the potential of the programme and is frustrated at the delays, however, we are getting to the point where, having spent so much money both in funding the system and keeping it running, the time is quickly approaching to make tough decisions on what the future of the project should be."