Sen. Jim Talent

— As Mitt Romney’s campaign readies for the South Carolina presidential selection primary this weekend, they are yet again dispatching Missouri’s former U.S. Senator Jim Talent to denounce rival Newt Gingrich.

On a conference call with reporters Wednesday morning, Talent blasted Gingirch for policy positions he’s taken in recent years, including his negative comments about Paul Ryan’s budget portal, his opposition to the troop surge in Iraq, his comments about climate change with former Speaker Nancy Pelosi, and his most recent attacks on Romney’s work at Bain Capital.

Pointing to those positions, as well as his own unease when Gingirch was House Speaker, Talent said Gingich is not a “reliable” conservative.

“Gingich, if we nominate him, is going to be an unreliable candidate like he was an unreliable leader in the 90’s,” Talent said. “We can’t be in the situation where we have to hope he does something different than he’s been doing for the last 20 years.”

In addition to the call, Talent is featured in a new campaign web ad echoing similar themes.

Talent was one of the first in a series of Missouri Republican officials to back Romney’s campaign. Romney’s campaign touts support from Sen. Roy Blunt, Congressman Billy Long, and House Leader Tim Jones, among others.

The Romney campaign first deployed Talent to attack Gingrich in the weeks before the Iowa caucuses.