The GP and Conservative MP Sarah Wollaston is calling on homeopathy's governing bodies to make it clear to parents that their alternative remedies will not protect children from measles outbreaks.

Large numbers of children have not had the MMR (measles, mumps, rubella) vaccine, largely because of the scare that followed the publication of research by Andrew Wakefield in the Lancet medical journal in 1998 that postulated a link between the jab and autism. The research was later discredited and Wakefield was struck off by the General Medical Council for fraud.

In Wollaston's constituency of Totnes, Devon, the concern generated by Wakefield lingers on and is part of the reason, she believes, for a general distrust of vaccines and a reliance on homeopathy – remedies that are almost entirely water.

About 70% of five-year-olds in Totnes were fully protected against measles last year, she said on her blog, compared with 94% of those in Brixham, just miles away.

"Some parents have an unshakeable belief that homeopathy boosts their child's immune system. They would rather put their faith in 'natural' methods, as they see it," she told the Guardian.

That belief can spread in communities and outside school gates, and those who accept the NHS advice to give their child the MMR vaccine start to feel pressured.

"Once it reaches a critical mass within a community, it takes on its own significance – you become an irresponsible parent if you are vaccinating," she said. "I think it is time to dump this term 'herd immunity'. The message, as I see it, is about community immunity. By vaccinating your child, you protect the child who cannot be vaccinated as they are too young or sickly."

Wollaston called on the governing bodies of homeopathy to tell parents that homeopathic "vaccines" and remedies would not protect against measles.

The British Homeopathic Association and Faculty of Homeopathy said they would do so. "There is no evidence to suggest homeopathic vaccinations can protect against contagious diseases. We recommend people seek out the conventional treatments," a spokesman said.

"I don't know where the parents in Totnes are getting their information from – it certainly is not us. There is no legal regulation of homeopathy in the UK and anyone can set themselves up as an expert. It is those people who tend to give us a bad name."

Philip Edmonds, chairman of the Society of Homeopaths said: "The Society does not endorse the use of homeopathic medicines as an alternative to vaccination for the prevention of serious infectious diseases and recommends that members of the public seek the advice of their GP, and/or relevant Department of Health guidelines, concerning vaccination and protection against disease."

There are currently about 700 cases and suspected cases of measles in Wales, the biggest outbreak since the triple jab was launched in 1988. An estimated 40,000 children in Wales have not had the MMR, and special catch-up NHS clinics have been held for two weekends in a row in the worst-affected Swansea area.

Some parents continue to seek out single vaccines, against NHS advice. The Children's Immunisation Centre, which runs six clinics in England and one in Swansea, said it was being inundated with calls from parents seeking a measles vaccine.

"The clinics are very, very busy," said manager Zoe Miller. "It has made people realise, crikey, we have not vaccinated our children. They need to do it before it spreads to their children."

Miller said staff advised parents to give their children all three vaccines at intervals, but the chain of private clinics has no mumps vaccine and has not had any for three years.

Outbreaks of mumps, sometimes known as the kissing disease, can occur among students starting university. Although serious complications are rare, they can include viral meningitis and swelling of the testicles or ovaries.

"Mumps isn't life-threatening," said Miller. The vaccine, she added "is apparently available in Singapore". The clinics say they are attempting to source a Jeryl Lynn strain of mumps vaccine to import, which they say is the safest strain.

However, the Medicine and Healthcare Products Regulatory Authority, which licences vaccines in the UK, disagrees.

"The MHRA is not currently aware of any available single-component mumps vaccines for which there are no safety concerns," it said in a statement.

"In relation to the Children's Immunisation clinics, we have significant concerns over the quality of the mumps vaccine the clinic is attempting to supply."

The Department of Health's position is that there is no evidence to support the use of single vaccines or to suggest they are in any way safer than the MMR, which is supported by the World Health Organisation and other independent expert groups around the world. Giving children the single vaccine leaves them at risk of catching the other diseases in the intervals between jabs.