The NHS complaints system will need a "complete overhaul" to provide patients with an effective appeals process, the Commons health committee has announced.
The health service ombudsman should also have more powers to review complaints rejected by service providers, the committee said.
The comments followed an inquiry into the NHS complaints process. At present, procedures represented "a significant obstacle" to a successful complaints system, the health committee stressed.
"The ombudsman's current terms of reference prevent her from launching a formal investigation unless she is satisfied in advance that there will be a ‘worthwhile outcome'," said committee chair Stephen Dorrell. "We have concluded that this requirement represents a significant obstacle to the successful operation of the complaints system."
Mr Dorrell added that NHS culture was too often defensive and called for timely reports to be made of all patient complaints.
Mr Dorrell also called for greater clarity on how the complaints procedure would work under the reformed NHS. "It remains unclear how patients' complaints about services delivered by primary care will be handled following passage of the health and social care bill," he explained.
The committee also expressed concerns over proposals to reduce access to legal aid for clinical negligence cases. It stressed: "The committee warns ministers that the public will judge these proposals by how they alter access to justice."
The Patients Association welcomed the comments, saying the complaints procedure was "misleading and disheartening".
"We have stated time and time again that the NHS complaints process is failing patients," said Patients Association chief executive Katherine Murphy. "How can a system hope to be fair and impartial when it relies on the trust investigating itself?"
She added: "We welcome the recommendation by the committee that trusts must publish a complaints action plan to show how they will address any weakness in the trust that was highlighted by the complaint. But this must not just be a publication that is ignored by regulators and other responsible bodies. Monitor, Healthwatch England and the CQC must make sure they are scrutinising any action plans that are produced by a trust and ensure that promised changes and put in place."