Olds

But campaigners say they are outdated and do not ensure products are nutritionally appropriate or stop them being promoted to four month olds.

Ofcom's own research found that 59% of 13 to 17-year olds surveyed had seen "potentially harmful content" online in the previous month.

But some nurseries say the money they receive for three-and-four-year olds is not enough and they can no longer subside it with the money parents pay for younger children - as from September the state will be paying for 80% of childcare in England.

After the ban was announced, researchers found a decline in the number of vapers mainly using disposable e-cigarettes - in all age groups and particularly among 16-24 year olds.

But 13 to 15 year olds must obtain parental permission to turn off such settings - which can only be done by adding a parent or guardian to their account.