ST. PAUL, Minn. (AP) — Former Minnesota Sen. Paul Wellstone's sons are being pushed out of the campaign organization dedicated to their father's legacy.

Wellstone Action told Mark and David Wellstone on Wednesday they'll be voted off its governing board in the coming days.

The group's leaders say the move follows months of tension as the brothers have pushed to make Wellstone Action more vocal in Democratic politics. It currently focuses on training liberal-minded candidates for races ranging from school boards to legislatures to Congress.

Wellstone's sons co-founded the group after the 2002 plane crash that killed Wellstone, his wife and daughter. The organization has trained thousands of candidates and campaign managers.

Co-founder and board member Jeff Blodgett says it was a sad but necessary step. David Wellstone didn't immediately respond to requests for comment.