‘The only thing green about him is the slime in his veins’

The 29-year-old, a leading activist with Plane Stupid and a veteran of several daring stunts, would not countenance flying. On Friends Reunited, she declares: "I have begun to finally direct my arsy attitude towards felling the establishment and saving the world."

Ms Deen was first arrested in 2005 after climbing a crane to protest at the G8 summit in Scotland. Two years later she superglued herself to the Department for Transport's doors and two days ago she disrupted a speech by Transport Secretary Geoff Hoon by sounding a klaxon, or "lie detector horn", when she thought he had told an untruth.

Last Boxing Day she set off for Morocco with sister Emma, 31, and their mother Sheila. It took three days to get there by train and boat. "I wouldn't let her fly there," said Ms Deen. Although her mother was allowed to return by plane, Ms Deen took the overland route once more.

At the family's £500,000 home in Brighton today, her mother said: "I am proud she has the courage of her convictions. I was happy to take the train with her to Morocco. She hasn't flown for at least three years."

Ms Deen, who works four days a week for an anti-poverty charity, has spent all her adult life in a sub-culture of demos, campaigns and protests, many dreamed up at her rented flat in Hackney.

"I have a normal life as well," she laughed. "I wouldn't expect a boyfriend to do what I do but I do find it difficult to go out with men who do not care about social justice."

She got into activism at state school in Brighton, aged 17, organising protests against cuts in student grants. "My mother brought me up to speak my mind," she said. At Leeds University where she studied international development, she campaigned against tuition fees and the Sun newspaper which she got banned for being biased against asylum seekers. She said as her father was from Egypt she found its views particularly hurtful. In fact her parents split up when she was young and she has not seen her father for many years.

After Leeds, she flirted with film-making "but film people were idiots" and journalism before turning to charity work and protest. "It is fun," she said. "People in this community are passionate about making a change."

Ms Deen and fellow activists will next be seen en masse in the City on 1 April in a Climate Camp to coincide with the G20 gathering of world leaders. A variety of stunts can be expected. At least politicians know where she will be that day. It's the rest of the time that must worry them.