City lawyers called on local Boy Scout officials to muster "the courage of their convictions" and challenge their national group's ban on gays as a trial over government funding opened Tuesday.

The city of Philadelphia wants to end its $1-a-year lease to the local Boy Scouts chapter unless it rejects a Boy Scouts of America policy banning "avowed" gays. The city says the national rule violates a local law banning discrimination on sexual-orientation and other grounds.

Local scout chapters, including the Cradle of Liberty Council in Philadelphia, have struggled in recent years to satisfy both public and private funders as well as their national leadership's dictums. The Boy Scout oath calls for members to be "morally straight," which the national group interprets to mean that gays cannot participate.

In 2004, the Philadelphia chapter agreed to ban any "unlawful" discrimination. But the city said the policy didn't go far enough, given that the U.S. Supreme Court in 2000 had said scouts and other private organizations can legally restrict membership.