Although, once again, a lot more than just an extreme right winger:

“The white supremacist and child sex offender was reportedly left disfigured after he was attacked by a fellow inmate at HMP Wakefield in West Yorkshire.”

https://www.lep.co.uk/news/crime/lancashire-nazi-who-plotted-to-kill-mp-stabbed-in-prison-attack-5472435

Stabbed because he was a sex offender or for his political views?

Both crimes were abhorrent, as was the knife attack.