The Chamber of Commerce has launched a new ad urging conservatives to support comprehensive immigration reform, featuring the words of three potential 2016 presidential candidates -- Sens. Marco Rubio (R-Fla.), Rep. Paul Ryan (R-Wis.) and Sen. Rand Paul (R-Ky.).

But Paul on Sunday came out against the current bill, saying he will vote against it because it doesn't include his border security proposal. Paul has otherwise said he supports the idea of comprehensive immigration reform, as long as its done right.

"Let's secure our borders, welcome our new neighbors and practice the values of freedom and family," Paul says in the clip used in the ad.

While the ad doesn't take a stand on the Senate bill -- instead urging them to merely support "conservative immigration reforms" -- the Chamber as an organization has endorsed the Senate bill and worked toward its passage.

The ad is part of a reported seven-figure ad buy from the Chamber. The Senate is set to vote Monday on the new border security agreement crafted by Sens. Bob Corker (R-Tenn.) and John Hoeven (R-N.D.).