WASHINGTON ― Fired-up House appropriators are expected to vote Tuesday to reject the Pentagon’s requests for added budget flexibility over the President Donald Trump’s diversion of military funds to build his promised U.S.-Mexico border wall.

In a sign of fraying relations between the Department of Defense and Capitol Hill, the House Appropriations Defense Subcommittee ― chaired by Indiana Democratic Rep. Pete Visclosky ― “condemned” the Pentagon’s past approvals of nearly $10 billion over two years toward the border wall, saying it had fueled the panel’s growing skepticism over the department’s budget requests.

“The granting of additional budget flexibility to the Department is based on the presumption that a state of trust and comity exists between the legislative and executive branches regarding the proper use of appropriated funds. This presumption presently is false,” the subpanel said in its 400-page report accompanying its fiscal 2021 defense spending bill.

The full House Appropriations Committee is set to mark up and approve the bill on Tuesday.

The Pentagon relies on legal authorization to transfer funding between accounts and manage contingencies, and it requested $9.5 billion this year. But a key provision in the bill would cap the authority at $1.9 billion.

The defense spending bill contains multiple provisions aimed at reversing Trump’s move, in February, to divert $3.8 billion from weapons programs and other DoD accounts for the wall. One provision in the defense bill would require the DoD return unobligated funds taken for the wall in fiscal 2020 to their original accounts.

It’s the latest in a series of countermoves by lawmakers since Trump, after being denied billions of dollars he requested for the wall, declared a national emergency in 2019 to siphon the money from defense accounts. The project was Trump’s signature campaign promise in 2015, but his method has sparked bipartisan claims he’s usurping Congress’ power of the purse.

The defense subpanel’s top Republican, Rep. Ken Calvert of California, blamed Democrats for their refusal to fund the wall but also expressed sympathy with his infuriated colleagues.

“I’m all for the wall, but I understand the tension here because these were duly passed appropriations bills,” Calvert told Defense News. “I don’t care if the president is a Republican or a Democrat. We don’t want presidents unilaterally bypassing Congress to do their will.”

Still, he said, “the absolute inability for the Democrats to negotiate, the frustrations in the administration [led it to] just grab the money and go ahead because the president made a promise, he made a commitment to do this.”

Beyond the border wall, the word “disappointed” appears 12 times in the report, which rapped the Pentagon on weapons programs, transparency and its repeated requests to fund off-budget overseas contingency operations. Multiple administrations and Congress have repeatedly used wartime funding to absorb base budget costs.

Though the U.S. is withdrawing forces from war zones, the Pentagon had planned to request $60 billion in OCO through 2025.

“The OCO experiment has been an abject failure and has given the Department a budgetary relief valve that has allowed it to avoid making difficult decisions,” the report read.

The defense report ripped the DoD’s “dismissive attitude toward oversight exhibited by the Department,” despite Congress’ approval of large budget increases over the last several years.

“When coupled with the Department’s disturbing actions over the past two years to fund the border wall, the contravention of the constitutional authority of the United States Congress has now become habitual,” the report read. “The Committee finds this to be both unacceptable and unsustainable.”