(CNN) House Democrats introduced a resolution Friday to block President Donald Trump's effort to build a wall on the southern border through his emergency powers, setting up votes in Congress to rebuke the President's proclamation, even though Trump has promised to veto the measure.

In a call with reporters, House Speaker Nancy Pelosi and Rep. Joaquin Castro, a Texas Democrat and the author of the resolution, argued that Trump's emergency declaration undermined Congress's constitutional power of the purse.

"The President's act is lawless," Pelosi said. "It does violence to our Constitution and therefore to our democracy. His declaration strikes at the heart of our Founders' concept of America, which demands separation of powers."

The Democratic-controlled House appears all but certain to pass the resolution Tuesday and put pressure on Republicans in the Senate, many of whom have concerns with Trump's action. Even Senate Majority Leader Mitch McConnell, who now supports the President's decision, had previously said he wanted to avoid it.

Still, even if the resolution passed, Trump could veto it -- as he promised to do in comments he made Friday from the White House -- forcing Congress to override it with a two-thirds majority in the Senate and the House.

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