Rep. Jeff Flake (R-Ariz.) called on leadership today to include a permanent ban on earmarks in a popular ethics reform measure working its way through the House.

Leadership was expected tonight to formally release the STOCK Act as well as allowed amendments, and it was unclear whether Flake’s ban would be included in the bill itself or as one of the amendments.

The House last year adopted rules banning the use of earmarks, and the controversial practice has essentially been eliminated in that chamber.

Nevertheless, in a letter to Speaker John Boehner (R-Ohio) and Majority Leader Eric Cantor (R-Va.), Flake pointed to a series of stories in the New York Times and Washington Post highlighting Members’ use of earmarks as proof that a permanent ban is needed.

“There is little arguing that stories like these, of which there seems to be no end, cast a shadow over Congress at a time in our history that would necessitate the utmost in trustworthiness with respect to fiscal matters. They allow for the appearance of impropriety that demands remedy,” Flake wrote.

“It would seem inconsistent for Congress to take steps to address the public’s concern over the appearance that Members are making themselves richer via their positions with respect to financial transactions while ignoring the very same appearance with respect to earmarking,” he added.

Although the earmark ban is popular with conservatives and the public, it is unclear whether Congress could pass legislation binding future Congresses, aides said.

“We already have an earmark ban in place, and it’s tough if not impossible for one Congress to bind a future Congress,” one GOP leadership aide said today.