Advocates for a bill that would add a vote for D.C. in Congress are asking supporters to call congressional leaders to revive the measure after it stalled in the House.

A controversial amendment that would repeal many D.C. gun laws has been attached to the voting rights bill and could derail the measure. The bill to add one vote in the House for heavily Democratic D.C. and another seat for Republican Utah passed the Senate last week -- the closest D.C. has come to a full vote in Congress in 30 years.

D.C. Del. Eleanor Holmes Norton said Tuesday that House leaders put the bill on hold when they learned the National Rifle Association was pressuring its members to keep the gun measure in the bill.

D.C. Council members have been debating whether to drop their support for the voting rights bill if the gun amendment remains attached.

On Wednesday, Council member Mary Cheh sent a letter to House Speaker Nancy Pelosi, Senate Majority Leader Harry Reid and House Majority Leader Steny Hoyer asking that if the gun amendment goes forward, a new amendment should be added to apply the same gun rules to the Capitol and federal buildings.

"If members of Congress are not willing to put themselves at risk with this additional amendment, they should eliminate the provisions that would endanger the people of the District of Columbia," Cheh wrote.

The gun amendment received strong support in the Senate. Democrats from pro-gun states such as neighboring Virginia supported the measure, along with most Republicans.