Zac Goldsmith MP joined the Mayor and hundreds of others in Barnes at a rally against Heathrow's third runway.
Richmond Council, which serves residents who live under the airport's flight path, is currently leading a referendum on the future of Heathrow.
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The London Marathon brings together thousands of people raising money for charity - not to mention some rather unusual costumes.
Planning on going to the London Marathon tomorrow? Read our handy guide first!
Celebrations to mark St George's Day have started in Trafalgar Square with feasts and tea to be found in abundance.