Patients could have to sign up to healthier lifestyles under new plans being considered by the Labour Party.
Smokers may be forced to try and quit in return for nicotine patches
Written contracts would ensure a certain standard of treatment in return for people following doctors' advice and attending appointments.
A party spokesman denied smokers or overweight people, for instance, could be refused treatment if they did not give up or diet.
But the plans have provoked a storm of protest. Claire Rayner, president of the Patients Association, called them a "nasty piece of political chicanery".
The proposals, which could become part of Labour's manifesto at the next General Election, are aimed at addressing the pressures put on the NHS by avoidable illnesses such as smoking.
The Times newspaper said new contracts would give patients methods to demand a standard of care.
In return patients would be expected to play their part by heeding instructions such as nutritious eating or attending a programme to conquer an addiction.
A consultation paper will be discussed at Labour's annual conference and the eventual results will form the basis of the party's manifesto.
The proposals refer to the NHS as a "free, yet finite service" where waste must be cut back.
In return for nicotine patches, you have to go to courses to help you give
It says: "The concept of reminding patients about the limits of the National Health Service and about their responsibility in using its resources sensibly is one we want to take forward."
The contract would set out standards of care but also "remind him or her of
the reciprocal nature of their relationship."
"This type of agreement would not be legally binding. It would take the form
of a joint statement of `mutual intent'," the Labour policy paper says.
A Labour spokesman said: "We are consulting on setting out clearly
what you can expect as a patient in the NHS.
"We also want to set out responsibilities people would have, for example not
to abuse NHS staff.
"It is not true to say if you didn't give up smoking you wouldn't be
"It could give people advice as we already do and help them.
This idea amounts to a bureaucratic nightmare
"In return for nicotine patches, you have to go to courses to help you give
"The right is you can have the drug. The responsibility is that you have to take part in the programme."
The proposals have been given a cool response from opposition politicians and patient groups.
HAVE YOUR SAY
Such a regime would free up more resources for those in need
Robert Crosby, Nottingham, UK
Shadow Health Secretary Dr Liam Fox said: "This is yet further interference by the government in how health professionals should treat their patients.
"Since these contracts will not be binding on either party it seems this will just mean more red tape at a time when doctors are having to spend too much time filling in forms and too little time seeing their patients."
Paul Burstow, Liberal Democrat health spokesman, said: "The danger is that initiatives such as this will not give us a patient-centred NHS.
"They could end up putting power back in the hands of providers, in this case those who
issue the contract."
Ms Rayner said the logical conclusion of the plan would be to deny somebody treatment if they were hit while crossing the road because they were looking the wrong way at the time.
She said many health problems were inextricably linked to poverty, and complex social issues.
If it was that easy to change your lifestyle people would be doing it already
"This is another piece of political manipulation of the nastiest kind.
"I find it repellent, and no patient of any sense is going to fall for it.
"Let's have a bit of intelligent dialogue on this, not this finger-wagging, contract-making nonsense. It just won't work."
Lyndel Costain, of Dieticians in Obesity Management UK, said action to tackle smoking and obesity would be welcome - but questioned the merits of the new proposals.
"Changing day-to-day behaviour such as what we eat is very hard work.
"It's engrained into people's cultures and depends upon how much money we have to spend.
"It can be difficult for people with less money to buy the healthier food. And some people use food to cope with stress.
"If it was that easy to change your lifestyle people would be doing it already.
"People need help from the NHS and if changes are to be made there must be support available to them."
Dr John Chisholm, chairman of the BMA's General Practitioners Committee, warned that the proposal would jeopardise the relationship that doctors had with their patients.
He said: "Patients do need to take responsibility for their health care and their lifestyle choices and doctors encourage them to do so.
"The NHS is not a limitless resource and it is right to exhort people to use it responsibly.
"But we would deplore any suggestion that people would be denied free care because of their failure either to take medical advice or to respond to that advice.
"At a time when we are working with the government to reduce bureaucracy in general practice, this idea amounts to a bureaucratic nightmare."