OTTAWA - Charles Caccia, a Liberal MP for more than three decades and passionate crusader on environmental issues, has died at age 78.

Caccia, who was first elected to the House of Commons in 1968, held the Toronto-Davenport riding through nine subsequent elections and served 36 years on Parliament Hill.

He was labour minister under Pierre Trudeau from 1981 to 1983 and environment minister in the short-lived government of John Turner.

Liberal Leader Stephane Dion, in a statement issued Sunday, paid tribute to Caccia as a "champion of environmental and social justice'' and called him "a great Liberal who dedicated his life to building a better Canada.''

Caccia left politics in 2004 after being squeezed out for the party nomination in his riding by Mario Silva, a supporter of Paul Martin in the leadership wars then plaguing the Liberals.

Long seen as one of the most left-leaning members of the Grit caucus, Caccia was a friend and political ally of veteran cabinet minister Sheila Copps and one of the few MPs to support her in a failed leadership bid against Martin.

He turned down an offer to run for the NDP after being elbowed aside by the Martin forces and continued to lend his support to the Liberals after his departure from Parliament.

Caccia also remained active on environmental issues, serving as a senior fellow at the University of Ottawa Institute of the Environment and as president of the group Green Cross-Canada.

He suffered a stroke a week ago and had appeared to be recovering, but took a turn for the worse on the weekend. He died Saturday.