Last year Londoners donated hundreds of gifts to children in Lambeth, Westminster, Southwark, Camden and Hammersmith and Fulham.
This year the appeal hopes to benefit those in care across all London boroughs.
Anyone wishing to donate a gift can collect a tagged ribbon from special Christmas trees in their borough or at New Scotland Yard, and follow the instructions on the tag.
Virtual ribbons can also be collected online at: www.met.police.uk/christmas-tree-appeal/.
Scotland Yard says gifts should cost no more than £20 and promises they’ll be delivered before Christmas day.
Sir Bernard was inspired to launch the appeal after seeing a similar scheme in Sheffield 30 years ago, when he was a PC on the beat.
The Commissioner got this year’s campaign underway last night by switching on the New Scotland Yard Christmas tree lights with the help of Harshita Ramanand, winner of the Met’s Christmas Tree Campaign poster design competition.
Sir Bernard said: “This is a simple idea in the spirit of Christmas. A child in need can be helped by a simple gift from someone they have never met. That person gains no recognition other than knowing they have shown some care for a child that needs a little more love than most.”