Doctors have expressed "grave concern" at figures showing only half of teenage girls are getting the vaccine to prevent cervical cancer.

At the beginning of the school year, only 50pc of girls had started the recommended vaccine dose - far short of the 80pc target.

The warning was issued by senior medics in the Royal College of Physicians.

They urged parents to vaccinate their daughters against "the very real risk that they will develop cervical cancer in later life".

The reduction in take-up, which saw a 15pc drop in vaccinations last year, has been linked to unfounded fears about the safety of the vaccine.

Prof Mary Horgan, a consultant in infectious diseases said: "The clinical evidence about the safety and effectiveness of this vaccine was so strong when it was initially developed that I didn't wait for it to become part of the national immunisation programme and went ahead and had my 13-year-old daughter vaccinated.

"That is how strongly I feel about it. Parents should feel fully assured that the vaccine is very safe and effective."

The European medicines watchdog investigated claims of the potential link between the vaccine and symptoms such as pains in the limbs and an abnormal rise in heart rate. It gave the vaccine the all-clear.

The college's president, Prof Frank Murray, said: "We as healthcare providers must collectively inform parents about the benefits of this vaccine and recommend that they consent to having their daughters vaccinated to protect them from becoming cancer patients in future years."

Prof Karina Butler, chair of the national immunisation advisory committee, pointed out it was important for parents to know that the earlier the vaccination was given, the better.

"As the vaccine is more effective the earlier it is given, we encourage all parents to have their daughters complete the recommended schedule of HPV vaccines: a two-dose HPV vaccine series before age 15, or three doses in those older.

"It is so tragic to see a young woman, often at the age when their family is still young, battling for her life against what is now a vaccine-preventable cancer."

The HPV vaccine protects against two types of viruses, HPV 16 and 18, the cause of 70pc of cervical cancers.