Paul Hellyer, the photographer who had accompanied Lees to Madagascar, described him as: "So single-minded and focused. It's a personal tragedy for me, a tragedy for his family and for the entire environmental movement in the wider sense."
Lees's counterpart at Greenpeace, the campaigns' director Chris Rose, spoke of Lees's "fanatical determination. Andrew had this incredible belief in the power of the truth," he said. "He was always trying to uncover things. He thought if you could get atthe truth and put it in front of people it would cause change."
Lees's actions were one of the most powerful catalysts for change over the last 20 years,Charles Secrett, director of Friends of the Earth, said. "He was a formidable campaigner and his death is a tremendous blow to the environmental movement. He was oneof our best and brightest stars."
The campaign Andrew Lees waged to bring pollution of drinking water to national attention was cited as one of his greatest achievements. Tom Burke, special adviser to John Gummer and a former director of Friends of the Earth, said: "He kept everything moving and made sure the Government and water authorities did what they were supposed to do."
Jonathan Porritt, special adviser to Friends of the Earth, who worked with Mr Lees on that campaign, said: "Andrew understood better than anyone else how European directives could be implemented. Our ministers were slow to realise the consequences of signing up and Andrew was red hot on pursuing them." He added that Mr Lees was "completely dedicated, very intense, professional and strangely intuitive. He had a real nose for winkling out what people didn't want him to know." Graham Wynne, director of conservation for the Royal Society for the Protection of Birds, campaigned with him against the drainage of Halvergate Marshes, Norfolk. ``From his early days in conservation when he fought against the pollution and loss of the wet meadows in the Broa ds, Andrew was totally committed and highly professional."
Personally people warmed to him. "He was the sort of person with a glint in his eye. You never knew how serious he was or how far he would go," he said.
Mr Secrett added: "He was a very funny bloke, generous and very aware of other people."
Tom Burke summed up: "He was a hero in his own way and a man who commanded enormous respect even among those who found him irritating. He made a difference."