WASHINGTON (Reuters) - Republican and Democratic U.S. senators plan to introduce as soon as Tuesday legislation that would force President Donald Trump to obtain Congress’ approval before imposing tariffs on national security grounds, a senior senator said on Tuesday.

U.S. President Donald Trump greets Republican Senators Bob Corker and Lamar Alexander after arriving at Nashville International Airport on Air Force One in Nashville, Tennessee, U.S., May 29, 2018. REUTERS/Leah Millis

Republican Senator Bob Corker, chairman of the Foreign Relations Committee, said legislation would be introduced on Tuesday or Wednesday that would pare back the president’s authority under Section 232 of the Trade Expansion Act of 1962.

Prompting criticism from many of his fellow Republicans as well as business groups, Trump decided last month to open a trade investigation into whether auto imports had damaged the U.S. auto industry, which could lead to tariffs of up to 25 percent on “national security grounds.”

Trump had cited similar security concerns in March in imposing duties on steel and aluminum.

Trump, who campaigned on a pledge to negotiate better trade deals to save U.S. jobs, has pursued aggressive measures against trading partners from China to Canada, Mexico and U.S. allies in Europe.

This has worried some Republican lawmakers who strongly back principles of free trade, warning that Trump could trigger a trade war that would destabilize the economy and ultimately hurt American workers.

“What this would do is redefine that and say that the president would go through the same steps that he goes through, but at the end of the day, if he decides that he wants to put tariffs in place, Congress would have to approve those,” Corker told reporters.

Corker declined to say how many other senators supported the legislation, but said there was “a big list” of both Republicans and Democrats.

Corker said backers might offer the measure as an amendment to the National Defense Authorization Act, or NDAA, a defense policy bill that is passed every year.

The Senate is expected to consider the NDAA as soon as this week.

That would increase its chances of becoming law, especially given likely resistance from Trump.

Republican Majority Leader Mitch McConnell said the Senate would not debate a free-standing tariff bill, but it could be introduced as an amendment to the defense bill.

Senator Chuck Schumer, the Democratic leader, said Corker’s legislation could get some Democratic support.