Senators Scott Brown of Massachusetts and Olympia Snowe of Maine are being targeted for ouster for supporting repeal of the military's ban on gay and bisexual troops serving openly.

The Republicans are among the five senators accused on Monday of being too liberal by conservative group the Tea Party Nation. Senators Dick Lugar of Indiana, Orrin Hatch of Utah and Bob Corker of Tennessee also made the list.

The group's founder, Judson Phillips, blasted Snowe and Brown for crossing the aisle to vote with Democrats on “Don't Ask, Don't Tell” and other issues, and accused the five senators of being Republicans In Name Only, or RINOs. The group called Brown “the biggest disappointment of the last year.”

A second conservative group, the Greater Boston Tea Party, is also openly talking about an early retirement for Brown.

“There's enough of an underground movement in the Tea Party movement as seeing him as not being conservative enough,” Christen Varley, the group's president, told the Boston Globe. “There probably will be multiple people who attempt to run against him [in 2012].”

Other Republicans who voted for repeal include Senators George Voinovich of Ohio, Mark Kirk of Illinois, Susan Collins of Maine, John Ensign of Nevada, Richard Burr of North Carolina and Lisa Murkowski of Alaska.