The U.S. House of Representatives will vote on Tuesday on a resolution aimed at stopping President Donald Trump’s declaration of a national emergency to build a wall on the border with Mexico, Speaker Nancy Pelosi said on Friday.


House Democrats introduced the resolution early on Friday, taking the first step to challenge Republican Trump’s assertion that he could take money Congress had appropriated for other activities and use it to build the wall.


Pelosi predicted the resolution would pass the Democratic-controlled House. Action would then move to the Republican-majority Senate, where the measure’s future is less clear.


About 226 House lawmakers have joined the sponsor, Democratic U.S. Representative Joaquin Castro of Texas, in backing the legislation. The co-sponsors so far include one Republican, Representative Justin Amash of Michigan, Castro said.


“What the president is attempting is an unconstitutional power grab,” Castro said in a conference call with reporters. He called on all members of Congress — Democrats and Republicans — to support the resolution terminating Trump’s emergency declaration, saying it tramples on congressional authority and would set a dangerous precedent.


Under the U.S. Constitution, Congress decides how taxpayer dollars are spent. The president can, however, veto spending bills.


Trump declared the national emergency last week after Congress declined to fulfill his request for $5.7 billion this year to help build the wall.


Senate Democratic leader Chuck Schumer also plans to introduce such a resolution. The measure needs only a simple majority in both chambers. It will need the votes of at least four Republicans to pass the Senate, assuming all the Democrats and the two independents there back it.


If both chambers pass the resolution it would then go to Trump, who would likely veto it. Overriding the veto would require a two-thirds vote of support in both chambers.


Pelosi rejected Trump’s argument that there is an emergency at the U.S.-Mexico border. “The president of the United States is declaring a national emergency to honor an applause line in a rally,” she said.


“If the Congress rolls over on this, the president is likely to do it again,” Castro said.


The issue is also in the courts. A coalition of 16 U.S. states led by California sued Trump and top members of his administration on Monday to block his decision to declare the emergency.


The lawsuit said Trump’s declaration was a misuse of presidential power.


Congress this month appropriated $1.37 billion for building border barriers following a long battle with Trump, which included a 35-day partial government shutdown - the longest in U.S. history - when agency funding lapsed on Dec. 22.