The leader of the Green Party last night launched a highly personal defence of immigration to Britain, drawing on her own experience of migrating from Australia as an adult.

Natalie Bennett told the audience at the BBC’s opposition leaders debate that she had made Britain her home after briefly visiting it because she was so struck by the country’s traditions and way of life.

“I’m an immigrant; I’ve chosen to become a British citizen, to make my life in Britain,” she said. “I came as a visitor, I loved the British way of life, I loved the traditions, the culture, and I decided to stay and make this my home.

“I went into politics because I want to improve that, I want to improve that, I want to protect it, and I want to make sure the vulnerable and the nature environment are protected.”

Ms Bennett has previously spoken of how she is not interested in returning to Australia, where she was born, partly because there is “a very strong strand of anti-intellectual thought in Australian life”. She has lived in London since 1999.

What Labour said on immigration Show all 7 1 /7 What Labour said on immigration What Labour said on immigration Ed Miliband Labour leader Ed Miliband was accused of telling MPs to "move conversation on from immigration," as revealed by a leaked document made available in December to The Telegraph PA What Labour said on immigration Diane Abbott Diane Abbott, MP for Hackney North and Stoke Newington, said: "Freedom of movement is an absolutely central component of the EU" Getty Images What Labour said on immigration David Lammy MP David Lammy said Labour's new "tough rhetoric" on immigration had upset his constituents Charlie Forgham-Bailey What Labour said on immigration Frank Field MP Frank Field was reported in December to have said that immigrants are contributing "a lot less" than people think to the economy Justin Sutcliffe What Labour said on immigration Chuka Umunna Shadow Business Secretary Chuka Umunna said: "People absolutely have legitimate concerns about controlling the numbers that come in and out" AFP/Getty What Labour said on immigration Lucy Powell MP Lucy Powell, Shadow Minister for the cabinet, is reportedly responsible for approving the leaflet that told doorsteppers to "move conversation away from immigration" What Labour said on immigration Yvette Cooper Shadow Home Secretary Yvette Cooper said: "Immigration is important for Britain but it has got to be controlled and managed so the system is fair for everyone" Getty Images

Told by an audience member that immigration had had a negative impact on public services, she replied:

“I’m afraid I entirely disagree with the premise if your question. What’s put our public services at risk is austerity, failure to invest and privatization, particularly of our NHS.”

Ms Bennett made good on her promise to Green Party activists that she would take on Nigel Farage, the leader of Ukip, who says immigration has had a negative impact on the UK.

“I live in Somers Town in central London, a very diverse community. There are migrants there, some of them are cleaners, some of them are doctors, some of them are grandmas. They’re all contributing to the British way of life in their own way,” she said.

“There’s someone here on this platform who wants to utterly demonise those migrants, and you know who I mean – I want to celebrate the contribution of migrants to Britain, and I believe we should all be doing that.”

The Green Party has made much of its support for migration in this year’s campaign, in contrast to the stance of the other parties.

After Labour launched a tea mug with “controls on immigration” written on the side, the greens responded by printing a batch of “standing up for migrants” mug – which sold out within hours.