The White House has outlined to lawmakers how it wants to at least start building the wall along the Mexican border and it isn’t going to cheap. In a move that could imperil any hope of reaching a compromise to protect undocumented immigrants who were brought into the country as children, the administration wants $18 billion over the next decade to build the first phase of the border wall. The Washington Post breaks it down:

The money would pay for 316 miles of new fencing and reinforce another 407 miles where barriers are already in place, according to cost estimates sent to senators Friday by U.S. Customs and Border Protection. If the work was completed, more than half of the 2,000-mile border with Mexico would have a wall or other physical structure by 2027.

The request, which was first reported by the Wall Street Journal on Friday, was part of a demand for $33 billion to secure the border and marked the first time the White House laid out a plan to fulfill on the president’s key campaign promises. Of that total, $5.7 billion would go to technology, $1 billion for road construction and maintenance, and $8.5 billion to hire more Border Patrol agents and related immigration officers.

The Customs and Border Protection documents that were sent to lawmakers detail “what a 2,026-mile border wall system would entail—comprising about 864 miles of new wall and about 1,163 miles of replacement or secondary wall—even as administration officials and their allies insist they are not pursuing a wall ‘from sea to shining sea,’ as Homeland Security Secretary Kirstjen Nielsen and her predecessor John Kelly have testified to Congress,” notes CNN.

Democrats in Congress immediately criticized the $18 billion request, describing it as a nonstarter that could imperil delicate budget negotiations and may very well assure a government shutdown later this month. “President Trump has said he may need a good government shutdown to get his wall. With this demand, he seems to be heading in that direction,” Sen. Richard J. Durbin of Illinois, the ranking Democrat on the Senate Immigration subcommittee, said. Durbin went on to call it “outrageous” that the White House would “undercut months of bipartisan efforts by again trying to put its entire wish-list of hard-line anti-immigrant bills—plus an additional $18 billion in wall funding—on the backs of these young people.”

Rep. Nancy Pelosi took to Twitter to tell the president “that border wall funding you are asking for (again) could do so much more good in other places …. #NoWall.”

THREAD: @realDonaldTrump, that border wall funding you are asking for (again) could do so much more good in other places…. #NoWall — Nancy Pelosi (@SpeakerPelosi) January 5, 2018

An administration official confirmed to the Associated Press that funding for the wall and additional cash to secure the border must be included in any immigration package. Earlier in the week, Homeland Security Secretary Kirstjen Nielsen had said wall funding would be “first and foremost” in any legislation that sought to protect the approximately 780,000 people who had been shielded from deportation under the Deferred Action for Childhood Arrivals Program.