Paul Whiteman, general secretary of school leaders' union NAHT, said: “This week we have seen guidance on mobile phones from government and a new dentistry duty from the opposition. This is not the immediate response needed to solve the mounting crises in school. We need to see greater ambition in the short, medium and long term.

"We have serious reservations about how such a policy could even work. It is not the role of teachers to be making sure children brush their teeth each day.

"Schools already play a role in teaching children about the importance of looking after their teeth through the curriculum, but there has to be a limit in terms of what we can expect them to do.

"We should demand more than window dressing from all of our politicians.”