By Susan Cornwell and Steve Holland
WASHINGTON/LONDON (Reuters) - U.S. Republican senators warned on Tuesday that the White House may not have support from members of their party in Congress for threatened tariffs on Mexican imports, while President Donald Trump said lawmakers would be foolish to try to stop his plan.
At a closed-door luncheon on Capitol Hill, Republicans told officials from the White House counsel's office about their concerns over Trump's threat to impose tariffs on goods imported from Mexico next week.
Senator Ron Johnson warned the White House not to count on the same level of backing it got from Republicans earlier this year, when Trump declared a national emergency to divert funds to build barriers at the border with Mexico.
Congress voted to reject that move by Trump, although just 12 of the 53 Senate Republicans joined Democrats then.
"We’re not real fond of tariffs, so don’t assume you can have the exact same level of support. That was my basic message," Johnson told reporters.
Senator John Thune, the Senate's No. 2 Republican, also told reporters a vote to approve tariffs on Mexico "would be a heavier lift" for Republicans than the border emergency declaration.
Earlier on Tuesday, Trump said he doubted congressional Republicans would follow through with any rebuke and that he expected tariffs on goods imported from Mexico to go forward next week.
"I don't think they will do that. I think if they do, it's foolish," Trump said at a news conference in London, where he was on a state visit to the United Kingdom, citing his broad support among Republican lawmakers.
Frustrated over the migrant crisis at the southern U.S. border with Mexico, Trump last week said he would impose tariffs on Mexican imports starting June 10. The president threatened to start the tariffs 5% and increase them to as high as 25% later this year if the Mexican government does not do more to stop the flow of Central American immigrants crossing Mexico to reach the United States.
Mexican officials, eager to avoid punitive tariffs and salvage a separate trade agreement between the two countries and Canada, have embarked on a diplomatic push in Washington to reach an agreement over the migrant flows.
Trump on Tuesday acknowledged the U.S.-Mexican talks this week but said the tariffs on one of the top U.S. trading partners were still likely.
At the Capitol, Senate Majority Leader Mitch McConnell sidestepped questions about whether lawmakers would vote to reject tariffs, telling reporters Senate Republicans simply hoped to avoid them. "There's not much support in my conference for tariffs. We're hoping that doesn't happen," he said.
The planned tariffs have been criticized by business and industry groups worried about increased costs for U.S. businesses and consumers.
Republicans and Democrats are also worried about the economic impact of the proposed tariffs, particularly for the U.S. agriculture and auto sectors. Tariffs could also derail a separate trade deal to replace the North American Free Trade Agreement (NAFTA) that the Trump administration is trying to get Congress to approve.
Senate Democratic Leader Chuck Schumer said he believed Trump would "back off" from his tariff threat when faced with the strong opposition. He predicted there would be a disapproval resolution from Congress if Trump moves forward.
Republican Senator Rob Portman said lawmakers would be forced to act because Trump was imposing the tariffs using his emergency powers, "which is going to require another vote of disapproval."
House Majority Leader Steny Hoyer, the chamber's No. 2 Democrat, said he was heartened that some Republicans had expressed concerns about the threatened tariffs.
"We may well have the opportunity in a bipartisan way to act on this," Hoyer told reporters.
(Reporting by Steve Holland in London and Susan Cornwell in Washington; Additional reporting by Makini Brice and Amanda Becker; Editing by Doina Chiacu and Bill Berkrot)