Emma Watson has revealed she became a feminist when she was eight years old, as she launched a new UN campaign.

The former Harry Potter star gave a passionate speech at the United Nations Headquarters in New York, for the HeForShe campaign for gender equality.

"I started questioning gender-based assumptions when at eight. I was confused at being called "bossy" because I wanted to direct the plays we would put on for our parents - but the boys were not," she said.

"When at 14 I started being sexualised by certain elements of the press. When at 15 my girlfriends started dropping out of their sports teams because they didn't want to appear "muscly". When at 18 my male friends were unable to express their feelings.

"I decided I was a feminist and this seemed uncomplicated to me. But my recent research has shown me that feminism has become an unpopular word. Apparently I am among the ranks of women whose expressions are seen as too strong, too aggressive, isolating, anti-men and unattractive."

The 24-year-old actress, best known for playing Hermione Granger in the Harry Potter films, was speaking out in her role as a UN Goodwill Ambassador.

"The more I have spoken about feminism the more I have realised that fighting for women's rights has too often become synonymous with man-hating. If there is one thing I know for certain, it is that this has to stop," Emma continued.

"I think it is right that as a woman I am paid the same as my male counterparts. I think it is right that I should be able to make decisions about my own body. I think it is right that women be involved on my behalf in the policies and decision-making of my country. I think it is right that socially I am afforded the same respect as men.

"But sadly I can say that there is no one country in the world where all women can expect to receive these rights."

The full speech, entitled Gender Equality Is Your Issue Too, is published on the UN website (http://www.unwomen.org/).