Former House of Representatives speaker Newt Gingrich is to run for president.
A spokesman said he will make the official announcement on Facebook and Twitter on Wednesday.
Mr Gingrich will offer his first speech as a presidential candidate at the Georgia Republican Party Convention on Friday.
He has made no secret of his White House ambitions and has been raising money and assembling a campaign team for months for the 2012 election.
Getting into the race marks a comeback attempt by the former congressman from Georgia who stepped down from the House in 1998 after four tumultuous years as speaker.
He had led the Republican Party to its first majority in the House in 40 years.