House Democrats aggressively questioned a federal agency Tuesday about a potential sale of the Trump International Hotel and whether the president and his family could sell the lease to a foreign government, a potential violation of the Constitution.

Emily Murphy, the head of the General Services Administration, declined to comment about the potential sale of the Trump Organization lease at the Old Post Office where the Trump International Hotel is located.

The government’s lease to the Trump Organization has been the subject of congressional scrutiny since Trump took office and declined to separate himself from his family’s eponymous business.

“President Trump is both the GSA’s tenant and its boss. That’s an obvious problem,” said Rep. Dina Titus, D-Nev., chairwoman of the House Transportation and Infrastructure subcommittee on public buildings.

Titus held the hearing on Tuesday as Democrats continue to seek documents from the General Services Administration about the lease to the Trump Organization, and whether the arrangement violates the emoluments clause of the Constitution.

Article 1, Section 9 of the Constitution prohibits any person holding federal office from accepting “any present, emolument, office or title of any kind whatever from any king, prince or foreign state.” And Article 2, Section 1 says the president may not receive, beyond his salary, “any other emolument from the United States, or any of them.”

House Democrats have argued in court filings that the president is in violation of Article 1, Section 9 since the Trump Organization profits from the use of the hotel by foreign governments and leaders.

A federal appeals court in July dismissed a lawsuit brought by the attorneys general of Maryland and the District of Columbia that alleged Trump was violating the Constitution, saying the states lacked standing to bring the case. The Justice Department argued in that case that the clause was never intended to apply to a president’s private business interests disconnected to his office or any service to a foreign government.

The Trump Organization has nonetheless decided to give up running the hotel in downtown Washington and is asking $500 million for the lease. During testimony Tuesday, the General Services Administration, which oversees government real estate and leases, noted it would not rule out a lease for the property to a foreign government.

Titus said selling the lease would benefit the president. She asked Murphy what percent of the sale would go to federal taxpayers, who own the property, but Murphy said she did not know.

“The Trump Organization is violating the law and the Trump administration is letting them get away with it. It’s an obvious conflict of interest,” Titus said following the hearing. “The potential transfer of hundreds of millions of dollars into the president’s pocket creates even more legal and ethical issues that the Trump administration is desperate to ignore,” she said.

The government would have 45 days to approve a lease once the Trump Organization identifies a potential business willing to buy the lease.

The Office of the Inspector General of the General Services Administration issued a report last year that concludes Trump failed to separate himself from his business interests and that the agency should have conducted a legal review of the lease of the Old Post Office building.