One thing that I thought was nifty when I was considering the local vocational school program as an option at that age was that there actually were a few very part-time jobs available at the vocational school. Only for a handful of hours a week, but you could actually essentially make a bit of money while you were at school! Though those jobs were won by just a few individuals, the ones who performed best in the program.
For this specific program the students do not have to pay, which is something that's emphasized when they're advertising it to the students. There are paid tuition vocational schools for students who drop out of high school or who graduate on the standard path and want vocational training, although those are subsidized by the government to some degree as I'm sure the ones in the UK are.