The investigation into why poorer women have a higher risk of the disease found they tended to have sex about four years earlier than more affluent women.

Previously, it had been thought the disparity was the result of low screening uptake in poorer areas.

The International Agency for Research on Cancer findings are published in the British Journal of Cancer.

Although the difference in cervical cancer incidence between rich and poor – across the world – had been noted for many years, it was not clear why this is the case.

Especially as rates of infection with human papillomavirus (HPV) – the sexually transmitted infection linked with the vast majority of cervical cancers – seemed to be similar across all groups.

The study confirmed that the higher rates of cervical cancer were not linked to higher HPV levels.

But what it did reveal is that the two-fold increased risk was largely explained by women from poorer backgrounds starting to have sex at a younger age.

The age at which a woman had her first baby was also an important factor.

Screening was found to have some effect on the level of risk.

But the number of sexual partners a woman has and smoking did not account for any of the difference.