There is now "sufficient evidence for a realistic prospect of conviction" of PC Alex MacFarlane, a Crown Prosecution Service review concluded.
Lawyers studied footage appearing to show the officer say to a 21-year-old black man: "The problem with you is you will always be a n*****, yeah?".
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The average temperature for this time of year in London is 16C, the weekend will be seven degrees above average.
Nearly 50 people were forced from their homes as London Fire Brigade cordoned off the area around Brickfield Cottages, in Plumstead.
The decision on how officers will give evidence to the investigation into the controversial police tactic will be made public today.