Texas Congressman Ron Paul plans to announce on Tuesday in Iowa that he is forming a presidential exploratory committee.
Drew Ivers, Paul's 2008 Iowa caucus campaign manager, said the Republican congressman will announce his plans Tuesday afternoon at Des Moines hotel.
Paul also will name an Iowa campaign team at the event, Ivers said.
Paul, 75, finished fifth in the 2008 caucuses and has visited Iowa seven times since. He headlined an event in Sioux Center two weeks ago for a social conservative group, and he spoke at a rally for Christian home-school advocates at the Iowa Capitol in Des Moines last month.
Paul is a favorite among libertarians and enjoys strong backing by many tea party supporters.
News of his decision to form a committee came on the same day that Republican Gov. Haley Barbour bowed out of presidential contention, thinning the ranks of potential candidates only 18 months before the 2012 election.
So far, former Massachusetts Gov. Mitt Romney, who lost the nomination in 2008, and former Minnesota Gov. Tim Pawlenty, who was on John McCain's vice presidential short list, have set up presidential exploratory committees allowing them raise money for full-fledged campaigns. Former House Speaker Newt Gingrich is expected to make his campaign official as early as next week.
A cluster of lesser-knowns also have inched toward the race, including former Pennsylvania Sen. Rick Santorum.
Unlike four years ago, GOP presidential hopefuls have been hesitant to rush into the race. Many have been mindful of the long slog and huge costs of a campaign. Several also have been waiting to see what the first half of the year would bring, when the focus would be on the new House GOP majority and its tangles with the Democratic administration.
Paul's bid for the White House would be his third attempt. He ran as the Libertarian Party candidate in 1988, finishing with less than one half a percent of the vote. He tried again in 2008.
The lawmaker is known for his libertarian views and folksy manner, giving him an edge with the Tea Party.