'There was no way I was going to let my kids have the triple vaccine … there's autism in my family'

So when his own daughter, now aged eight, got to the age where she needed vaccinating against measles, mumps and rubella he paid for her to have single vaccines at a private clinic.

There were no ill effects, so Ben embarked on a similar course with his younger son, now aged two, earlier this year.

The toddler started on a course of single vaccines, getting the measles jab first.

But when Ben, 34, from Glasgow, made an appointment for the mumps and rubella jabs he received the news that there was no longer any mumps vaccine available.

He said: "I was completely bewildered and frustrated.

"I believe in immunising children, and I have read all about the need for herd immunity.

"There was no way I was going to let my kids get the MMR because there is autism in my family, which we believe is linked to the triple vaccine.

"So I did the responsible thing and tried to make sure that my son was fully vaccinated with the single jabs.

"Now I am told that there is no more mumps vaccine left and they will not be making any more.

"It's just unbelievable that my family has been put in this position. When we started on this course of action, Merck were quite clear that they would be resuming production.

"Now they have just changed their mind. It does raise some questions in my mind as to why they have done this. Have they been leaned on by the government to stop single vaccine production? "

Jackie Fletcher, who runs the Jabs support group for parents whose children have suffered through vaccinations, said hundreds of concerned parents had contacted her about the mumps jab shortage.

She said: "There are thousands of people all over the country who are now in a terrible quandary.

"Many simply do not think MMR is safe. But they do want to get their child immunised.

"It is a disgrace that they are now in a position like this."