Boris Johnson tweeted this picture of him with Hollywood legend Will Smith saying 'great to see Will Smith, @officialjaden & 90 kids at my Leadership Club achievement events today.'
More top news
The 34-year-old victim was left with a huge gash across her nose and face. Police need to find a man seen on CCTV.
The girl was travelling on a train from London Liverpool Street to Romford in Essex after going to see the poppies at the Tower Of London.
Wealthy businessman Ivan Massow wants to succeed Boris Johnson at City Hall in 2016.