The Government adviser who first recommended the introduction of the MMR vaccine for all children admitted yesterday that the policy was not working and called for parents to have the freedom to choose a single jab instead.

Eileen Rubery, who led the committee that backed the measles, mumps and rubella jab in 1994, said the decline in parental confidence meant a different approach was needed.

Dr Rubery, who was head of public health at the Department of Health and who still acts as a consultant to government, said: "I still think the MMR vaccine is the vaccine of choice for parents but what I think one has to accept is that the present policy from the Department of Health is not working.

"Their own figures say that 84 per cent of two-year-olds are vaccinated. That's 10 per cent less than their target."

She suggested that ministers should consider allowing parents to choose, "because then maybe some of the parents will take up the single vaccine and that will increase the overall protection in the country".

She said parents would not be "dictated to" by government but, given the choice, most would choose the triple vaccine. They "would feel able to think about the situation and make an informed choice, rather than at the moment making an emotional judgement".

The Health Department rejected Dr Rubery's argument, insisting that fewer children would have the injections if single vaccines were available.