I thought I'd check, and GBH has a maximum penalty of life. According to the Crown Prosecution Service the prosecutor guidelines have been updated to advise them to press for this maximum sentence if they can demonstrate to the court that the defendant acted with "intent to maim, disfigure or disable".
https://www.independent.co.uk/news/...n-service-cps-east-london-burns-a7877311.html
And I have to say I hate it when people say "oh it's gang violence, normal people are safe." The country isn't divided into gangs, and all violence negatively affects the public peace. In this epidemic, however, it's clear that the types of attack and the profiles of the victims are not typical of the kind usually dismissed as "gang violence."