The four-year-old is one of two girls who were ordered by a high court judge to have the jab for measles, mumps and rubella in a ruling on Friday. But according to a family friend, her mother is now seeking legal advice to stop the injection being administered.

Many parents fear the MMR vaccine could be linked to autism even though most experts say there is no evidence of a link. National take-up rates have dropped because of the concerns.

Neither the mother nor her daughter can be named for legal reasons, but Nick Skeens, a family friend who is helping them fight the case, said they were urgently seeking advice. "The judgment came through without us being informed. It took us all by surprise."

The cases, which were heard separately, were brought by the fathers of the girls. They want the children to have the protection of MMR injections.

"It's outrageous that, in a free society, a judge could make such a decision," said the mother of the four-year-old. "To date, vaccination has not been compulsory in Britain. This effectively means that any parent, indeed anybody, can launch a complaint against you, saying they don't like your beliefs - and want your child protected from your beliefs."

The girls, aged four and 10, lived with their mothers, who felt the combined vaccinations involved unacceptable risks.

The judge, Mr Justice Sumner, said the benefits of having the MMR jab outweighed the risks. "Recognising the anxieties of the mothers - the children's best interests are served by receiving a programme of immunisations."