Senate Majority Leader Mitch McConnellAddison (Mitch) Mitchell McConnellJuan Williams: Trump’s policies on race are more important than his rhetoric It’s Mitch McConnell’s Washington – and we’re just living in it Trump makes new overtures to Democrats MORE (R-Ky.) signaled on Wednesday that he will not support legislation reining in President TrumpDonald John TrumpKey takeaways from the Arizona Senate debate Major Hollywood talent firm considering rejecting Saudi investment money: report Mattis says he thought 'nothing at all' about Trump saying he may leave administration MORE's tariff authority and that the president will not sign such a bill.

"Yeah, I don't think we need to be trying to rein in the president through legislation. No. 1, it would be an exercise in futility because he wouldn't sign it," McConnell told SiriusXM when asked if he opposed the bill. 

McConnell was asked about legislation, spearheaded by GOP Sen. Bob CorkerRobert (Bob) Phillips CorkerDemocrats torch Trump for floating 'rogue killers' to blame for missing journalist Trump to send Pompeo to meet Saudi king Trump defends 0B US arms sale to Saudi Arabia MORE (Tenn.), that would require Trump to get congressional approval for any tariffs invoked under the national security sections of the trade law, known as Section 232. 
 
The legislation is backed by roughly a dozen senators so far, with several others indicating they are studying the bill, which was rolled out on Wednesday afternoon. 
 
ADVERTISEMENT
 
Trump sparked backlash from GOP senators after the administration went forward with slapping tariffs on steel and aluminum imports from the European Union, Canada and Mexico. The administration is also weighing a tariff on imported autos. 
 
The White House is stepping up its efforts to squash any momentum, as supporters look to try to get a vote as soon as this week on attaching the tariff legislation to an annual defense policy bill. 
 
Trump called Corker on Wednesday morning and asked him not to go forward with the legislation during a "lengthy" phone call. The president then reiterated his opposition to the bill, which he worries will hamper his negotiating authority, during a closed-door meeting with a group of GOP senators at the White House on Wednesday afternoon. 
 
McConnell told SiriusXM that he was "concerned" about the Trump administration's tariff decisions, adding that he hopes "this doesn't develop into a full-scale trade war." 
 
McConnell's opposition to the bill comes after he told reporters on Tuesday that he would not bring Corker's bill up on a stand-alone measure and said late last week that there was "not much" Congress could do legislatively. 
 
"I think the best tool for those of us who are concerned about this devolving into a full-scale trade war is to continue to try to convince the president that we need to not let this go on to long or go too far," McConnell added on Wednesday. 
 
Opposition to the bill from McConnell and the White House could prove critical to squelching support for it in the Senate, where the GOP leader is well respected and many Republican senators are wary of crossing the White House months before a midterm election.