WASHINGTON (AP) -- Colorado Republican Rep. Tom Tancredo, an outspoken opponent of illegal immigration, will announce his bid for president on Monday.

Tancredo will kick off his campaign with an announcement in Iowa, where political caucuses start the presidential nominating season, an official close to the congressman said.

Tancredo has flirted with a presidential bid for more than a year and began raising money for the effort in January. After taking in more than $1 million in two months, he has decided to make his run official, said the official, who asked not to be named ahead of Tancredo's official announcement.

Tancredo's office on Friday morning said that he will make a "major announcement" Monday on a Des Moines, Iowa, radio station.

Tancredo spokesman Carlos Espinosa would say only that Tancredo will announce his intentions and that his decision whether to run for president won't affect whether he will run again for his House seat.

Tancredo, a five-term House member who represents the Denver suburbs, is a leading supporter of securing the nation's Southern border with Mexico and cracking down on illegal immigration. He has used the issue to take on President Bush and Arizona Sen. John McCain, a leading contender for the GOP nomination.

Tancredo acknowledges that he is a long shot for president, but he has made no secret that he hopes to rattle McCain's campaign in Iowa by appealing to conservatives on immigration, abortion and other issues. McCain last year co-sponsored a bill creating a path to citizenship for the estimated 11 million illegal immigrants in the country now, though he has played a smaller role in the issue this year.(Related: Latest CNN/Opinion Research Poll shows Tancredo at one percent)