A trio of House committee chairmen are seeking answers from the White House and the acting head of the Department of Homeland Security (DHS) related to a politically motivated plan for undocumented immigrants in federal custody.

The plan from Donald Trump would involve moving immigrants in federal custody to so-called sanctuary cities, which are jurisdictions across the country that choose not to cooperate with federal immigration crackdown actions.

Such jurisdictions typically are governed by Democrats, and Trump has long been angry with Democrats for opposing his hardline immigration policies, particularly the wall he wants to build along the border with Mexico.

The committee chairmen sent a letter to the DHS and the White House requesting documents regarding the proposal to release detained immigrants into congressional districts represented by Democrats for purely political reasons.

The letter follows the president’s acknowledgement that the administration is actively considering this proposal and his claim that he has the “absolute legal right” to release immigrants into sanctuary cities across the country.

The letter was signed by House Judiciary Chairman Jerrold Nadler (D-NY), House Oversight and Reform Chairman Elijah Cummings (D-Md.), and House Homeland Security Chairman Bennie Thompson (D-Miss.).

“We are deeply troubled by multiple reports, recently confirmed by the President, that the Trump Administration is considering releasing detained immigrants into congressional districts represented by Democrats in a bizarre and unlawful attempt to score political points,” the chairmen wrote. “Not only does the Administration lack the legal authority to transfer detainees in this manner, it is shocking that the President and senior Administration officials are even considering manipulating release decisions for purely political reasons.”

Although Trump claims to have an “absolute legal right” to undertake this latest immigration scheme, that’s not actually true, according to Jake Tapper, of CNN.

DHS General Counsel John Mitnick provided the White House a three-part legal analysis why it would be illegal, Tapper said.

One part of the analysis found DHS is not allowed to spend its money to do this, to transport these individuals, unless it’s for a “clear agency-related purpose” such as providing medical care to individuals or facilities becoming overcrowded, Tapper said.

“And the underlying message is: ‘We can’t do this for political reasons, that would be against our charter, that would be against the law,'” he said.

Mitnick made two other points, Tapper said.

“This would open up the agency and the U.S. government to lawsuits because you’ll be denying due process to these individuals,” Tapper said.

“And if you do this, the odds that these individuals do not show up for their deportation hearing are much stronger,” he added. “So in other words, you’ll be undermining the law and you’ll be undermining your own purpose of wanting these people to go back where they came from.”