Parents are being warned of a possible outbreak of measles because the number of children having vaccinations has fallen to critically low levels.

Brighton and Hove has one of the lowest take-up rates of the MMR vaccine in the South-East.

Only 71 per cent of children were vaccinated between April and June this year compared to 75 per cent the previous quarter.

This is well below the regional and UK averages of about 84 per cent.

A report to the Brighton and Hove City Primary Care Trust warns if uptake rates do not improve, there is a risk of measles, mumps and rubella re-emerging in the city.

The report found a "significant" number of parents were refusing to let their child be immunised because of fears of a possible link between the MMR vaccine and autism and Crohn's disease.

Angela Iversen, consultant in communicable diseases at the trust, said: "At the moment we do not have any outbreaks of the disease in the city but that could change.

"Extensive research has been carried out by the Department of Health and there is no evidence to support the concerns about the vaccine."

Health officials warn it could take only one child to develop measles for the disease to spread rapidly.

The World Health Organisation recommends about 95 per cent of children in a community should be vaccinated to avoid an epidemic.

The report says some of the children may have been vaccinated privately with a single dose vaccine, which is not available on the NHS.

The Department of Health insists children get the best protection if the MMR jab is given as three separate vaccinations.

But many parents are campaigning for the choice to give their children a single vaccination.

For more details about MMR, log on to www.mmrthefacts.nhs.uk or www.immunisation.org.uk