The White House is preparing a plan to ban diesel exports for 90 days, Politico reported, citing unnamed sources. The legal process for such a ban remains unclear, though President Donald Trump is inclined to put a ban forward by week’s end, Politico reported.

Such a ban, if imposed, would mark the most sweeping step yet by the Trump administration to ease surging fuel costs, underscoring the pressure Republicans face ahead of November elections that threaten their control of Congress. Earlier this week, Trump had said he’s encouraged his advisers to support a ban on US diesel exports, with wars in Iran and Ukraine driving the fuel’s price to record levels.

Still, energy industry figures staunchly oppose possible export restrictions they say would provide only short-term price relief before ushering in even higher costs for fuels. US retail diesel prices have soared to all-time highs, reaching a record above $6.50 a gallon, according to the American Automobile Association.

Diesel futures in the US dropped sharply on the Politico report, falling more than 7% before paring some of the losses. European gasoil futures, meanwhile, jumped.