As an elected representative for the people of London, Ken should have some insults that are not 'Anti Semetic'.
Here are a few he could use, with out all the costs of the 'N' word:
Piss off
Nob head
Winkle
You smell of piss
Your mum smells of piss
Your dad is a tramp
Blood claat
Bumba claat
Tit
Arse
Bum face
You have bad breath
You
Muppet
Clown shoes
The list of PC insults is endless.
Don't use an insult that will upset a small minority.
Use an insult that is wide reaching, you 'Spam Head'.