The top two Democratic leaders on Monday told President Trump that any bipartisan infrastructure package needs to take into consideration climate change and include “substantial, new and real revenue” — a preview of the coming fight over tax hikes.

Trump will host Speaker Nancy Pelosi (D-Calif.) and Senate Minority Leader Charles Schumer (D-N.Y.) at the White House on Tuesday for discussions on a major infrastructure bill, one of the few policy areas that could see action amid divided government and as the 2020 race heats up.

But the two sides are far apart over how to pay for the transportation-focused package.

Democrats want the measure for roads, bridges, waterways and other projects to be paid for with tax increases, and with a final price tag of at least $1 trillion. The White House’s infrastructure plan is scaled back and relies heavily on public-private partnerships.