Three pro-gun interests have hired lobbyists, according to registration statements filed with the Senate Monday and last week, in the face of a push by Congress to introduce new gun control measures in the wake of the December massacre in Newtown, Connecticut.

That includes two companies — a Virginia firearms importer called Red, White and Blue LLC and Dick's Sporting Goods, a national chain that sells firearms, according to registrations filed Monday. Another group, the National Association for Gun Rights, has registered a lobbyist for the first time too, according to documents filed last week.

These registrations come on the heels of a pro-gun control nonprofit group, the Mayors Against Illegal Guns Action Fund, disclosing the the hiring of its second lobbying firm, JBH Group, last week. Mayors Against Illegal Guns Action Fund is a 501(c)4 organization that is not required to disclose its donors; it is well known that the group is bankrolled by New York Mayor Michael Bloomberg.

MORE: For data on the gun debate, see the Sunlight Foundation's resource page.

Dick's Sporting Goods, which banned the sale of "modern sporting rifles" after the Newtown incident, hired Monument Policy Group, its first lobbying firm since 2007.  Among the lobbyists at Monument is Stewart Verdery, Jr. who was Republican counsel for the Senate Judiciary Committee, which plans to take up gun control legislation this week. Verdery's former boss, Orrin Hatch, R-Utah, is the second ranking Republican on the panel. The former Senate staffer is one of nine lobbyists on the Dick's Sporting Goods account, most of whom are former government officials. The roster includes Ryan Spangler, a former deputy scheduler to Vice President Joe Biden while he served in the Senate. Biden is leading the White House's push for firearm legislation.

Dick's hired Monument to lobby on a range of issues, from firearms to taxes. Dick's supports the recently introduced Marketplace Fairness Act, which allows states to collect sales taxes from online retailers that are not based in their state. Monument has been working for the Pittsburgh-area company since January.

Red, White and Blue LLC, has hired Richard Egle of Egle Associates to lobby the House Foreign Affairs Committee on a so-called "Third Party Transfer initiative," documents show. Neither Egle nor the company could not immediately be reached for comment.

The National Association for Gun Rights is more clear about its objectives. The group will be lobbying on the three main gun-related issues before Congress right now: Enhanced background checks, the assault weapons ban and limits on magazine capacity, its report shows. The National Association for Gun Rights has criticized its older and better-funded rival, the National Rifle Association, for supporting tighter background checks.