PORTLAND — Former U.S. Sen. George Mitchell will address one of Maine’s leading environmental advocacy groups today when it presents its annual awards.

Mitchell will give the keynote address at the annual meeting of the Natural Resources Council of Maine. The meeting, at the Portland campus of the University of Southern Maine, will also include an announcement of the council’s annual environmental awards recipients.

On Friday night, the Maine Democratic Party will hold a tribute to Mitchell at the party’s annual Jefferson-Jackson Dinner fundraiser, in Portland.

Serving as a Democratic senator from Maine, Mitchell led the 1990 reauthorization of the Clean Air Act, and sponsored the first national oil spill prevention and cleanup law. Most recently, he served as U.S. special envoy for Middle East Peace from January 2009 to May 2011.