Washington (CNN) - The National Rifle Association is gearing up to face one of the strongest challenges to its cause in many years: recommendations from an Obama administration working group on gun violence that are expected to address assault weapons and high-capacity magazine clips.
CNN has learned the NRA is also preparing an ad campaign, expected to include both print and television advertisements, that would begin soon to help mount its opposition to new gun restrictions. NRA officials refused to discuss specifics.
The administration's working group on violence, led by Vice President Joe Biden, will deliver its recommendations to President Barack Obama by Tuesday.
"We are mobilizing for a fight," NRA President David Keene told CNN. "We will engage our members."
The association is planning to send mailings to its members urging them to contact members of Congress with their opposition to new gun laws. "Let them know you feel strongly," is how Keene summarized the group's message to member.
The NRA is also sending personnel to gun shows to help to mobilize gun owners to voice their opposition.
Since the shooting in Newtown, Connecticut, last month, the organization has added 100,000 new members, bringing its total membership to 4.2 million, NRA officials told CNN. Because of the increased attention on the issue, the officials think they will soon hit 5 million.
The NRA was one of the groups representing gun owners that met with Biden and his group Thursday afternoon.
After the session, the group issued a statement, saying "this task force spent most of its time on proposed restrictions on lawful firearms owners … it is unfortunate this Administration continues to insist on pushing failed solutions to our nation's most pressing problems."
A White House official did not comment on the meeting other than to say it lasted just over an hour and a half.
Biden earlier in the day told a separate meeting of his working group, this one with victims' groups and gun safety organizations, that "there's got to be some common ground here, not to solve every problem, but diminish the probability that … these mass shootings will occur and diminish the probability that our children are at risk in our schools."
Keene told CNN's "The Situation Room" that one area where he thought the group and the Obama administration could possibly find some common ground was on the need for background checks. However, he said he did not support instituting them at gun shows. Currently buyers at gun shows do not have to undergo the same background checks as buyers at gun stores.