US Republican Newt Gingrich will announce plans to run for his party's 2012 presidential nomination on Wednesday, his spokesman said.
Mr Gingrich, a former speaker of the US House of Representatives, will announce his candidacy via Twitter and Facebook, and will speak on Friday at a gathering of the Republican Party in his home state of Georgia.
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 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 for 40 years.
The 67-year-old has some of the best name recognition in the still wide-open race for the Republican presidential nomination, but he also has many political liabilities, including his three marriages.
Any Republican could have a hard time defeating President Barack Obama in next year's election as Mr Obama is expected to raise massive amounts of money.
His approval ratings have also received a boost following last week's military mission that killed Osama bin Laden.
A spending fight between Mr Gingrich and President Bill Clinton led to a shutdown of part of the federal government in 1995 and 1996. He left Congress in 1999.
Since leaving office he has set up a lucrative network of non-profit and business ventures. He has also churned out a steady stream of books and made frequent speaking engagements.
In recent months Mr Gingrich has lambasted Mr Obama's federal health law and has criticised the Democrat's foreign policy as "clueless."
He is dogged by extramarital affairs and having been married three times. He has been working to make inroads with social conservatives critical to the Republican primary base, highlighting his conversion to Catholicism after marrying his third wife, Callista.
Agencies