Several tea party leaders announced plans Thursday to form a national federation to promote the movement’s conservative message and to counter the idea that the tea parties are politically unsophisticated and disorganized.

Tea party leaders from Memphis, Tenn., Richmond, Va., and Orlando, Fla., along with representatives of several other groups announced the new National Tea Party Federation during a rally outside the Minnesota Capitol. They said 21 tea party groups around the nation had joined the federation.

Memphis Tea Party founder Mark Skoda said recent media coverage had questioned whether the conservative tea parties, which number in the thousands nationwide, were too loosely organized to be politically effective in the national midterm election. He said the federation intends to convey a unified message about the tea party’s brand of fiscal conservatism, which emphasizes limited government, less public spending and free markets.

He said the organization also hopes to rebut allegations about the movement: “Everything from calling the tea party members racist, that we are violent, that somehow we are fermenting another Kristallnacht. These accusations are indeed false and they won’t stand.”

The organizers said that the federation does not intend to direct activities by the farflung groups, but to improve communications among them, along with affiliate groups such as Americans for Tax Reform, Let Freedom Ring and Citizens United.

One of the affiliated organizations, the Family Research Council, works primarily to oppose abortion rights and gay marriage. Skoda said the tea party movement would not make those issues part if its core mission but could still find points of common ground with conservative social-issue groups.

“The family needs to have low tax rates, choice on health care, no mandate on health care, and the automony to make decisions. The family is an important part of our strategy,” Skoda said.

Many tea party groups don’t have formal memberships but Skoda said the movement represents about 500,000 people. Republican U.S. Rep. Michele Bachmann of Minnesota, a tea party favorite, participated in the rally.