(Claritza Jimenez/The Washington Post)

House Republicans with oversight over the nation’s capital are investigating D.C. Mayor Muriel E. Bowser’s plan to use local tax dollars to defend illegal immigrants from deportation.

The mayor received a letter Wednesday from Reps. Jason Chaffetz (R-Utah), chairman of the House Oversight Committee, and Mark Meadows (R-N.C.), head of the subcommittee for District affairs, warning her that her plan appears to violate federal law.

Bowser (D) this month joined leaders from Chicago, Los Angeles and New York in announcing that their cities would set up legal defense funds to represent illegal immigrants targeted for deportation under the policies of President Trump.

The fund would “double down” on the District’s status as a “sanctuary city”, Bowser said. D.C. police are already instructed not to ask those they stop or arrest about their immigration status, and city corrections officials provide only limited help in identifying nonviolent criminals to federal agents for deportation.

Bowser said the $500,000 fund would be used to teach the city’s estimated 25,000 illegal immigrants their rights and to hire lawyers to represent city residents in deportation proceedings and help them apply for asylum.

Rep. Jason Chaffetz (R-Utah) is the chairman of the House Oversight and Government Reform Committee. (Andrew Harrer/Bloomberg News)

The District’s complicated financial relationship with the ­federal government, however, means that Washington may have less latitude than other cities to carry out its plan.

Because the District is a federal territory, local lawmakers cannot spend any of the city’s local tax revenue — which tops $7 billion annually — in ways that conflict with federal spending rules. And a decades-old federal law known as the Immigration and Nationality Act says that no taxpayer money can be used to assist illegal immigrants in fighting deportation.

Chaffetz and Meadows cited the law in their letter and ordered Bowser’s office to turn over all documents related to the planned fund, including any internal legal documents drafted to defend the mayor’s proposal, and a list of outside organizations that could receive grant money from the fund.

“The District’s planned use of funds . . . to pay for legal representation of individuals subject to removal proceedings appears to be in conflict with existing federal law,” Chaffetz and Meadows wrote.

A spokeswoman for the House Oversight Committee declined to comment.

Bowser said the congressional investigation highlighted anew the District’s need for statehood and the “special” burden the city’s residents face. “These are the types of questions we will be called to answer,” she said.

How sanctuary cities work, and how Trump’s executive order might affect them

The letter from Chaffetz and Meadows arrived as Trump was at the Department of Homeland Security announcing an executive order to build a wall along the U.S.-Mexico border and to ramp up deportations of illegal immigrants.

Trump’s order instructed his administration to identify federal funding that could be withheld from the District and other cities if they maintained sanctuary policies.

D.C. budget officials said the order could wreak havoc on the city, potentially jeopardizing billions in annual assistance.

But as mayors nationwide weighed in with defiant statements, Bowser’s office remained quiet for more than three hours.

Bowser later said that the District would remain a sanctuary city, but added that the letter from Chaffetz demanding that the city produce documents had complicated its response to Trump. Aides to the mayor said she had held a long conference call with Del. Eleanor Holmes Norton, the District’s nonvoting representative in Congress, to plan a response.

It is not the first time that Chaffetz has tussled with Bowser.

Two years ago, the oversight chairman raised the prospect of the mayor facing jail time for violating federal drug laws if she implemented a voter-approved ballot measure that legalized marijuana.

Bowser allowed a partial legalization, letting adults to carry and privately consume marijuana. But she did not press a bigger showdown with Chaffetz over taxing and regulating it, as Colorado and other states have done.

The District has been left with one of the nation’s most disjointed marijuana policies, in which possession is legal, but sales and purchases remain illegal.

Chaffetz dropped the matter amid warnings by then-President Barack Obama that the White House supported the District’s right to set its own drug laws.

With a Republican in the White House, it is unclear how far House Republicans may now go in asserting control over the District.

This week, the House passed a bill that would permanently ban the District from spending its own tax money to subsidize abortions for low-income women. The White House issued a statement saying the president would sign the bill.

Efforts to roll back D.C. gun laws also have been introduced in the House.