Senate Democratic Whip Dick Durbin warned a government shutdown is a very real possibility while condemning a White House immigration plan that demands an additional $18 billion in funds to construct a U.S.-Mexico border wall.

“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,” the Illinois Democrat said in a statement Friday.

“It’s outrageous that the White House would undercut months of bipartisan efforts by again trying to put its entire wish-list of hardline anti-immigrant bills — plus an additional $18 billion in wall funding — on the backs of these young people,” the statement continued. “Bipartisan negotiations continue in good faith among senators who understand what is at stake, and I will continue my efforts to reach a bipartisan agreement.”

The administration is requesting the $18 billion to go toward a “border wall system” over the course of the next 10 years, according to a White House document that a bipartisan group of senators received on Friday.

The document notes that it does not include additional Trump administration immigration priorities, including ending the diversity visa lottery program and family-based immigration laws, which were drafted largely by White House senior policy adviser Stephen Miller.

The request calls for 722 miles of border wall. This includes constructing 316 miles of a new wall and 407 miles of “replacement and secondary wall.”

“Border wall system is a critical capability that provides ‘impedance and denial’ giving the Border Patrol the ability to slow and stop illegal cross border activity,” the document says.

The plan also requests $5.7 billion over the course of five years to go toward technology, such as drones and sensors, to help secure the border; $1.025 billion over five years to update and create new roads; and $8.5 billion over seven years to increase security personnel, such as border patrol agents and Air and Marine Operations agents.

Republicans and Democrats are vying to pass bipartisan legislation that would enhance border security and also would protect those covered by the Deferred Actions for Childhood Arrivals program from deportation. Democrats insist that the deal be included in a spending bill that must be passed prior to Jan. 19 in order to prevent a government shutdown.