A 10-year-old schoolgirl who has become the face of an animal rights campaign stood in solidarity alongside hundreds of protestors to plead: “Save the dolphins” from slaughter in Japan.

Diamond Demirbasa was one of the youngest campaigners at a national rally outside the Japanese embassy in Piccadilly on Friday to protest against the mass killing and capture of wild dolphins in Taiji Cove.

The day before she had given an impassioned speech in Hackney about the slaughter to more than 200 people at a screening of Oscar-winning documentary The Cove, at the invitation of the film’s star and leading campaigners against dolphin hunting, Ric O’Barry.

Diamond, who attends St Michael’s School in North Road, Highgate, said: “Dolphins are one of my favourite animals and they don’t deserve to be treated in this way and be captured.

“It’s really bad because they are killing innocent animals. It’s very selfish, very greedy of them, they are just not caring.”

Animal lover Diamond started fighting for dolphin rights after she overheard her mother’s friend Nicole Venter, who leads London Against the Dolphin Massacre campaign group, talk about the annual hunt of the creatures in Taiji.

Every year, fisherman capture thousands of dolphins to sell some to marine parks and aquariums, while killing the rest.

The schoolgirl, who lives with her mother and brother in Lawn Road, Hampstead, said the shocking revelations made her determined to take up the cause.

Diamond, who wants to become a politician or an activist like Mr O’Barry, said: “I wanted to participate as much as possible and make sure everyone knows this is happening.”

She rallied her classmates to make posters, urging them to raise awareness of the annual slaughter, and wrote her first ever speech, which she sent to Mr O’Barry.

He then asked her to perform it to inspire protesters before the rally on Friday.

Her campaigning drive has earned her a role as a young ambassador of the London Against the Dolphin Massacre group.

For Christmas, she has asked friends for one or two pounds towards flights to Germany instead of presents, so that she can take part in another protest in January.

Her mother, Carla Mccarogher, 34, a PA, said: “There’s no stopping Diamond when she puts her mind to something.”