Washington, DC (LifeNews.com) -- A pro-life congressman from Colorado is the latest to file papers to establish an exploratory committee for a potential bid for the Republican nomination in 2008. Pro-life Rep. Tom Tancredo joins a crowded field of Republican contenders including some who appeal to pro-life voters and others who don't.

Tancredo said he plans to file papers this week but won't give up his House seat unless he decides to run for president for certain.

Known as an outspoken opponent of illegal immigration, Tancredo told the Associated Press that he may run because voters in Iowa, the first caucus state, told him that other candidates don't share his views.

''They believe that there is a void in this race that none of the other candidates are willing or able to fill,'' he said.

Campaign spokesman Tim Haley told AP that Tancredo would also push his pro-life views in addition to the immigration issues.

Tancredo has been a solid pro-life vote in Congress and earned a 100 percent pro-life voting record from 2005-2006 from the National Right to Life Committee.

During the 109th Congress, Tancredo voted against funding either abortions in various situations or embryonic stem cell research. He voted repeatedly to uphold parental consent and notification laws on abortion and supported a bill telling women of the pain their baby will feel during an abortion procedure.

Tancredo has a perfect pro-life voting record with the group dating back to 1999 with the exception of one vote on a bill that NRLC worried would ration health care for seniors by limiting their access to prescription drugs paid for with their own funds.

The congressman joins top-tier potential candidates such as former New York mayor Rudy Giuliani and Arizona Sen. John McCain. However, both support forcing taxpayers to fund embryonic stem cell research and Giuliani backs legalized abortion.

Former Massachusetts Gov. Mitt Romney opposed both but he is a recent pro-life convert while Sen. Sam Brownback is seen by many as the strongest pro-life candidate in the field.

Other potential Republican candidates include former Wisconsin Gov. Tommy Thompson, who backs embryonic stem cell research, pro-life ex-Oklahoma Gov Frank Keating, pro-life Nebraska Sen. Chuck Hagel, and former Virginia Gov. Jim Gilmore who backs abortion but also some limits on it.