Bound over for £ 200 and 2 years. Or 100 hours of community service. But you get a book deal out of it
Formally:-
A person convicted of treason is liable to imprisonment for life or for any shorter term.[64] A whole life tariffmay be imposed for the gravest offences
the Truss rabble were talking of bringing in a revised Treason Act but given the Braverman would be drafting it is unlikely to pass - people are squeamish about burning people at the stake these days