You can't work:

without an employment permit issued by the education department of the local council

in any industrial setting eg factory, industrial site etc
during school hours
before 7.00 am or after 7.00 pm
for more than one hour before school
for more than four hours without taking a break of at least one hour
in any occupations prohibited by local by-laws or other legislation eg pubs, betting shops
in any work that may be harmful to your health, well-being or education
without having a two week break from any work during the school holidays in each calendar year