Gay and lesbian rights marches in Washington this weekend will do little to pressure lawmakers, Rep. Barney Frank (D-Mass.) said this weekend.

Frank, one of three and arguably the most prominent openly gay member of Congress, downplayed the impact of planned marches in D.C. in an interview with the Associated Press.

"The only thing they're going to be putting pressure on is the grass," he said.

"Call or write your representative or senator, and then have your friends call and write their representative or senator," the veteran lawmaker added. "That's what the NRA does. That's what the AARP does."

This weekend's activities will coincide with President Barack Obama's planned speech before the annual dinner Saturday night of the Human Rights Campaign, the largest advocacy group for LGBT Americans.

That community has voiced some frustration toward the president for a perceived slowness to address key issues, such as repealing the "Don't Ask, Don't Tell" and Defense of Marriage Act Policies.

Obama will seek to quell some of those concerns during his speech this evening.