The Trump administration, along with the president’s personal lawyers, are preparing to formally tell Democratic lawmakers seeking years of Donald Trump’s tax returns to get lost, The Daily Beast has confirmed.

On Tuesday, the administration will hit the deadline imposed early this month by Rep. Richard Neal (D-MA), chairman of the House Ways and Means Committee, who has demanded six years’ worth of President Trump’s long-hidden tax returns. Neal had also asked for returns for the president’s trust and seven entities in the Trump business empire, arguing that Congress has the authority to obtain the president’s tax returns under existing law.

According to two administration sources with knowledge of the matter, the U.S. Department of the Treasury is not going to comply with the deadline to hand over the returns, and officials plan to formally convey this decision to the committee in a letter. It is unclear if this letter will be transmitted on Tuesday.

The decision to buck Congress is not surprising, as Trump has steadfastly refused to turn over his tax returns in the past. But it moves the two branches of government even closer to a vicious legal fight that could take months or years to resolve. Earlier this month, Trump attorney William Consovoy wrote a letter to the Treasury Department’s general counsel Brent McIntosh, arguing “why Chairman Neal cannot legally request—and the IRS cannot legally divulge—this information.” (The IRS is a bureau of Treasury, which is headed by Steve Mnuchin, who is copied on Consovoy’s original letter.)

When asked by The Daily Beast if the Treasury Department would adhere to the Democrats’ demands by the Tuesday deadline, one administration source simply laughed and said, “Hell no, are you kidding?” Mnuchin himself said his department wouldn’t meet a previous deadline set by congressional Democrats.

Democrats on the committee have said that if the Trump administration continues to fight their formal demand for Trump tax returns, they are prepared to issue subpoenas for the relevant material. When asked for comment on the likelihood that Democrat lawmakers will now resort to legal action, Trump’s personal attorney Rudy Giuliani replied: “Let them knock themselves out.”

The battle over Trump’s tax documents is hardly the only one the president’s armada of personal lawyers are busy fighting. In a filing revealed on Monday morning, the president and his outside counsel took the extraordinary step of suing Rep. Elijah Cummings (D-MD), chairman of the House Oversight and Government Reform Committee, in an effort to thwart a congressional subpoena of separate Trump financial records. This month, Cummings subpoenaed Mazars, an accounting firm used by Trump and his business. In court documents, the lawyers for the Trump Organization argued that this kind of oversight of the president is illegitimate since it did not to advance a legislative agenda.

“We will not allow congressional presidential harassment to go unanswered,” Jay Sekulow, another one of President Trump’s personal lawyers, who defended him during Special Counsel Robert Mueller’s probe, said in a statement on Monday. Sekulow is overseeing Consovoy’s work for the president.

When asked by The Daily Beast if Trump is also going to sue any other Democratic lawmakers on other committees looking into his finances or taxes, Sekulow indicated such legal action would be weighed if a committee chair sent a related subpoena, noting, “Each will be reviewed when issued.”