LUFKIN, Texas (AP) _ A federal judge Thursday barred the back-to-nature Rainbow Family from holding a ''tribal council'' on government forest land this weekend.

U.S. District Judge William Wayne Justice accepted a federal magistrate's opinion that the gathering of about 500 people could violate ''laws relating to drugs and nudity in such substantial numbers that law enforcement would be rendered effectively unmanageable.''

Prior to the ruling, Rainbow Family spokesman Stephen Principle said the weekend council, as well as a July event that could draw 20,000 people, will go on despite efforts by the U.S. Forest Service to block the gatherings.

''I don't know who can stop this,'' Principle said. ''All our literature every year has said, 'Ignore any rumors of cancellations, regardless of source.'''

The Rainbow Family, a peace and environmental group with no leader and no headquarters, was invited by the Forest Service to apply for permits to hold the gathering but declined. The organization said it never seeks permits.

Lufkin is 119 miles northeast of Houston.