Railing against the "swamp," Roy objected to speeding the measure through a nearly-empty chamber, complained it wasn't paid for and challenged a decision not to include President Trump's $4.5 billion request for dealing with the migrant crisis on the U.S.-Mexico border.

Under House rules, it only took one opposing member to derail the vote. The package likely will now be delayed at least until early June.

Democrats slammed Roy in response. Rep. Donna Shalala, D-Fla., called the turn of events “tragic.”

House Appropriations Committee Chairwoman Nita M. Lowey, D-N.Y., said in a statement it is "deeply disappointing that House Republicans are now making disaster victims wait even longer to get the help they need."

The surprise development comes after the Senate overwhelmingly approved the legislation Thursday afternoon to help several states and Puerto Rico recover from hurricanes, floods and wildfires – this, after Trump himself backed off from his demand that border security money be added.