"I agree New Judge but if the military aspect is kept to a minimum (ideally dropped altogether) I think it could work"
So not really "National Service" in the accepted sense, then. For that matter, neither is the plan proposed by M. Macron:
"The first phase is a mandatory one-month placement with a focus on civic culture, which the government says will "enable young people to create new relationships and develop their role in society".
Voluntary teaching and working with charities are among the options being looked at, alongside traditional military preparation with the police, fire service or army.
The second phase is a voluntary placement of at least three months and up to a year, in which young people will be encouraged to serve "in an area linked to defence and security" - but again, they could opt to carry out volunteer work linked to heritage, the environment or social care."
It actually sounds like a load of nebulous waffle (as one would expect, coming from a senior politician whose grandiose plans - which were not very grandiose at all - have effectively been kicked into touch).
If such a scheme were introduced in the UK it would cost an absolute fortune to administer, it would almost certainly be "privatised" meaning an army of executives would be taking home footballers' salaries, it would face legal challenges, it would achieve very little and would be widely avoided. Complete and utter waste of time and money trying to get people to do things they don't want to do. Far better to spend that money helping people who want to do useful things for the country to do them.