Just to emphasise, the mandatory school leaving age is not changing. There is no massive expansion of sixth forms in progress so the numbers staying in school to 18 probably won't change much. What is changing is that young people who have reached the school leaving age but are not yet 18 must, if they are not in school, be undertaking full time training or receive training as part of an apprenticeship or receive at least 280 hours relevant training per year whilst in a full time job. Strictly speaking, the mandatory age to stay in education is not changing but a new mandatory age to stay in education or training is being introduced.
The law passed by the last government does not clarify how all these extra training places will be provided or who meets the cost, although it does say that an LA must provide "such services as it considers appropriate to encourage, enable or assist the effective participation of those persons in education or training". It leaves policing attendance of young people in education or training to LAs. Given the range of options available to young people it would not surprise me if a significant number slip through the cracks.
It appears the intention of the legislation is that non-compliance should be mainly dealt with by taking action against the young person concerned, although there is also provision for parenting orders to be used where the court thinks that will be effective in getting the young person to comply.
The view of the LGO on interpretation of the law is not final. It can be challenged in the courts. The relevant legislation clearly requires the LA to have a transport policy for young people of sixth form age which, amongst other things, must specify "the arrangements that the authority consider it necessary to make for the provision of financial assistance in respect of the reasonable travelling expenses" for children attending sixth form. That falls short of a requirement to provide free transport.
I originally thought that free transport would extend to those staying on in school but that was due to being taken in by the publicity stating the last government were raising the school leaving age. I should have checked the legislation properly. Now that I have done so I am increasingly of the view that the LGO is correct that LAs are not required to provide free transport. However, as LAs increasingly withdraw free transport from sixth form pupils there remains the question as to whether or not it is valid for LAs to decide that little or no financial assistance is necessary for reasonable travelling expenses.