The U.S. Chamber of Commerce, a group that regularly spends millions to boost business-friendly congressional candidates, will endorse former state Sen. Bradley Byrne in Alabama’s 1st District special election on Tuesday.

The chamber will endorse Byrne over GOP businessman Dean Young, a social conservative whose views align with the tea party movement, in the Nov. 5 GOP primary runoff to replace former Rep. Jo Bonner, R-Ala.

The Byrne endorsement marks the chamber’s first big move to combat tea party conservatives in the GOP whom they blame — along with many Americans — for the shutdown of the U.S. government earlier this month.

Their support also helps boost Byrne a week out from the GOP primary runoff, which will determine the next member of Congress from this deeply conservative district. GOP presidential nominee Mitt Romney received 62 percent of the vote here in 2012.

The chamber is not the first major endorsement Byrne has received in this race. The National Rifle Association threw its support behind Byrne. Bonner also backed Byrne’s candidacy earlier this month.

Alabama’s 1st District is rated a Safe Republican contest by Rothenberg Political Report/Roll Call.