London Mayor Boris Johnson on the Andrew Mitchell row:
"In my book you shouldn't abuse police officers and I made that clear loads of times. The crucial thing for me is that Andrew Mitchell has now apologised not just once but twice publically. I believe he's also apologised to the officer concerned."
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The 6km bike track will include 130m of the South Circular near Kew Bridge.
The unfortunate officer was taken to a central London hospital for treatment and his condition is not life-threatening.
Detectives investigating the Parsons Green terrorist attack have arrested a 17-year-old boy in Thornton Heath, south London.