Plans to address the problem of bulging A&E departments "lack sufficient urgency", MPs have warned.
The Health Select Committee said it was not convinced the proposals were an "adequate response" to the growing crisis in emergency care.
Health Secretary Jeremy Hunt has previously admitted that the "huge pressures" in A&E reflect other problems in the health service because accident and emergency is the barometer for the whole system.
And health experts warned that the emergency care system could collapse in six months as a result of rising demand.
To address the problems, NHS England ordered local health authorities to form "urgent care boards" to ensure that all A&E departments had "recovery and improvement plans" in place.
But MPs raised concerns about the boards, saying that experts who gave evidence to them were "unclear" about how many of these boards were planned, what powers they will have and whether they are voluntary or compulsory, temporary or permanent, established structures or informal meeting groups.
Committee chair Stephen Dorrell MP called on NHS England to ensure that the recovery plans are agreed in each area before the end of September.
"We were not convinced that the plans presented to us represented an adequate response to the challenges the system faces," he said.
"The committee is mindful of pressures which will build during next winter and is concerned that current plans lack sufficient urgency."
He added: "We were concerned that witnesses disagreed about the nature of demand for urgent and emergency care. The system is 'flying blind' without adequate information about the nature of the demand being placed upon it."
MPs also said the decision to launch the troubled NHS 111 service in April - replacing NHS Direct as the number to call for urgent but non-emergency care - was "premature".
The line suffered many teething problems, with patients complaining of calls going unanswered, poor advice given and calls being diverted to the wrong part of the country.
Just a month after its launch, medics warned that the ''problematic'' roll-out of the system left many patients not knowing where to turn and many said troubles with the service heaped pressure on already struggling A&Es.
The committee's report states: "It is clear from the evidence presented to the committee that Ministers rolled out NHS 111 without attempting to interpret the evidence from pilots, which themselves were limited in scale and scope.
"NHS 111 was launched prematurely without any real understanding of the impact it would have on other parts of the NHS including emergency and urgent care."
Mr Dorrell added: "It is disappointing that the decision was made to launch NHS 111 when so little evidence had been gathered to support it.
"We are concerned that having to speak to a call-handler and going through a laborious triage process will only encourage patients to see A&E as their first port of call."
Health officials launched an investigation into the advice line after a number of potentially serious incidents, including three deaths, were linked to the service.
And at the start of the year, NHS England launched a review into urgent and emergency care, led by medical director Professor Sir Bruce Keogh, saying that urgent and emergency services must adapt to meet rising demand.
MPs made a series of recommendations for Sir Bruce to consider during the review process.
Mr Dorrell said: "It is clear that the structures established 60 years ago are not appropriate for the 21st century. We need to reorganise the way in which emergency and urgent care is delivered."
The committee said that there should be more "community-based urgent care services" to stop people going to A&E when they do not really need to.
They said that emergency care in hospitals "needs to change" and hospital officials must address low staffing levels in emergency departments and ensure more comprehensive out-of-hours cover from consultants.
And commissioners should better use ambulance service staff so they do not simply just transport patients to hospital but provide grater care to patients.
Dr Patrick Cadigan, registrar of the Royal College of Physicians, said: "'Until the problems in acute care are addressed, patients will seek care where the lights are on, which are currently overstretched A&E and acute care departments.
"This threatens the quality of patient care and puts unmanageable pressures on both hospitals and doctors."
Professor Norman Williams, president of the Royal College of Surgeons, added: "It is clear that the relentless pressure on our A&E service cannot continue and we support the committee's call for clearer information about the nature of the demand to support much-needed change."
Dr Cliff Mann, president of the College of Emergency Medicine, said: "Current coping strategies are untenable and unsustainable. With average spends of over £500,000 per trust on locums to staff emergency departments it is self-evident that the money exists to solve this crisis."
Health Minister Lord Howe said: ""We are absolutely clear that we must work differently to respond to the changing needs of our ageing population. Our immediate focus is on our most vulnerable and elderly and we have agreed a £3.8 billion fund which will focus on joining up services, so that health and care services work more closely together, keeping people healthier and treating them closer to home.
"We've also asked Sir Bruce Keogh to carry out a review into urgent care, looking at the pressures on emergency services.
"We are working closely with NHS England and will respond to the Health Select Committee's report in due course."
An NHS England spokeswoman said: "We will consider the report very carefully and will consider it when we report on our review into our urgent and emergency care, announced by Professor Sir Bruce Keogh in January this year.
"Most urgent care boards have now submitted their plans to address the issues in their local area to us for checking, and they will all have done so by early autumn."