Public satisfaction with the NHS has fallen dramatically, according to a report.
Satisfaction with the way the NHS runs fell from 70% in 2010 to 58% in 2011, the British Social Attitudes 2011 survey found.
Authors of the report, published by the King's Fund, said the drop was the biggest fall in one year since the survey began in 1983.
The study, which questioned 1,096 people about their views on health care between July and November last year, found that satisfaction with GPs dropped slightly from 77% in 2010 to 73% in 2011.
It also found slight drops in satisfaction with inpatient, outpatient and accident and emergency services.
Satisfaction with NHS dental services improved by five percentage points - from 51% in 2010 to 56% in 2011.
King's Fund chief economist John Appleby said: "The value of this survey is that it has tracked public satisfaction over a long period, providing an important barometer of how the public view the NHS.
"The run of year-on-year increases in NHS satisfaction had to come to an end at some stage, and it is not surprising this has happened when the NHS is facing a well-publicised spending squeeze.
"Nevertheless, it is something of a shock that it has fallen so significantly. This will be a concern to the Government, given it appears to be closely linked with the debate on its NHS reforms."
Health Minister Simon Burns said: "Our latest survey of over 70,000 patients shows that an overwhelming majority - 92% - say that their overall experience of the NHS was good, very good or excellent.
"The British Social Attitudes survey targets the general public rather than targeting people that have actually used the NHS, so responses are influenced by other factors. By its nature, it is not as accurate a picture as the data from patients.
"Our own polling of the general public, undertaken independently by Mori, shows that satisfaction with the NHS is broadly stable at around 70% over a similar and more recent time period."
NHS Confederation chief executive Mike Farrar added: "These results give us a sharp indication that the public have become worried and confused about what is going on with the NHS.
"It would appear very likely that much of this relates to the understanding and support for the recent reforms.
"It is really important that politicians and NHS leaders are engaging the public in the major debate about the NHS and how we need to change in order to sustain and improve the services they have come to expect and value over recent years.
"Any drop in confidence in the service or confusion about the nature of current reform is therefore troubling.
"Over the coming months, it is going to be more important than ever that the Government and the NHS communicate effectively the financial and service challenges we face."