A revolution in the way organs are donated for transplant is called for today by the government's chief medical officer as concern grows over the acute shortage of donors and the rise in unnecessary deaths.

An expert report to be published this week says that every major hospital in Britain must have an organ donor specialist skilled in persuading grieving families that the hearts, lungs, kidneys and other vital organs of their deceased relatives should be used to save the lives of others.

Sir Liam Donaldson, England's chief medical officer, will back the findings of the government's taskforce on organ donation, but wants to go further and introduce a new system of donation because the shortage of organs is so severe. Three people a day are dying while on the waiting list for a transplant as the demand for a new organ is rapidly outstripping their supply.

Donaldson is advocating a system of 'presumed consent', where everyone in Britain would be presumed to be a donor unless they had specifically opted out, or unless their families had objections.

'We have one of the lowest rates [of organ donation] in Europe, far lower than Spain,' he told The Observer. 'We have one thousand or more patients dying on the waiting list each year, and there is a lot of suppressed demand, with doctors not even referring patients on to the list because there is no hope for them. That is a lot of patients dying.

'I think at the moment people often don't know whether their relative would have wanted to be a donor. Families are being approached when they are in a very distressed condition and, faced with uncertainty, their default position is to refuse consent. Often the quality of their dealing with clinical staff is not as good as it should be - the dialogue could be better. It does require considerable skill to handle such sensitive situations.'

Today we reveal the heartbreak of those who are waiting for organs and the uplifting stories of families who have consented to donate, and launch a campaign for the UK to move to the new system of presumed consent so that hundreds more lives can be saved.

The taskforce, set up by Health Secretary Alan Johnson to look at how to improve donation rates, is now considering the proposals for presumed consent. Their report out this week will say that the first step must be for the NHS to provide highly skilled organ co-ordinators who would be able to talk with sensitivity to relatives at the bedside of their loved ones.

They believe that there could be a 50 per cent increase in donated organs if hospitals became better at dealing with the highly sensitive conversations that take place when a patient has been confirmed braindead. At present, around one-third of families refuse to give consent for organ retrieval, and even when a patient carries a donor card, many families still refuse.

Last night the Prime Minister threw his weight behind the campaign to change the system. He said: 'I fully support the campaign The Observer has launched on this issue.'

And in an interview with the Sunday Telegraph, Gordon Brown said: 'A system of this kind seems to have the potential to close the aching gap between the potential benefits of transplant surgery in the UK and the limits imposed by our current system of consent.'

Ministers will embark shortly on a review of the existing system, but want a nationwide debate on the issue. But patients' groups made it clear that they did not want to see too much political interference in the matter. Katherine Murphy, of the Patients' Association, said: 'We don't think a private decision, which is a matter of individual conscience, should be taken by the state. If people want to give the gift of life, that is their right, but it must be something that is a voluntary matter.'

Under the opt-out system, doctors would automatically have the right to take organs from patients unless the patient had registered their refusal during their lifetime, and as long as the family were in agreement.

There are 9,600 people waiting for an organ, but last year only 3,100 operations were carried out. Some people are flying abroad to have kidney transplants, but this leaves them at risk of picking up infections.

The report will call for a UK-wide organ donation body to be placed within the NHS. The body would manage a new group of more than 250 transplant co-ordinators who would be given a much bigger role in talking to relatives at an early stage, explaining the clinical guidelines and addressing their fears. Once the relatives had agreed that the patient's organs could be taken, the co-ordinator would oversee all the arrangements.

The taskforce, headed by Elisabeth Buggins, chairwoman of the Birmingham strategic health authority, will also recommend that specialist 'retrieval teams' should be run by the new agency. They would be sent out to 'harvest' organs from a patient, rather than relying on local teams.

Donaldson does acknowledge that some people will never want their organs, or their relatives' organs, to be given. He said if they moved to the new presumed consent system 'it would be made clear that they have an inalienable right to opt out.'