(CNN) - A federal judge told US House and Senate Democrats they can begin collecting financial evidence this week about Donald Trump's businesses for a lawsuit.
Judge Emmet Sullivan, of the US District Court in Washington, denied an attempt by the Justice Department to stop the Democrats from collecting information from the Trump Organization and to appeal early court decisions in the lawsuit, which tests the constitutionality of Trump's business holdings while he serves as President.
The case is one of several avenues Democrats have to get to Trump's financial records.
Sullivan said the group of more than 200 members can begin collecting evidence June 28 through late September. Previously, the members of Congress said they plan to seek both documents and depositions from the Trump Organization.
But the Justice Department had hoped to take the case to an appeals court before the evidence collection began.
"This case will be poised for resolution within six months; an immediate appeal would hardly materially advance its ultimate termination," Sullivan wrote on Tuesday.
House Speaker Nancy Pelosi praised the ruling and said in a statement, "No one is above the law -- not even the President. Once again, the courts have resoundingly reaffirmed our efforts to hold the President accountable for corruption, and ensure that the President acts in the public interest, not his own interest."
This may not be the end of the fight for Trump's records, however.
The Justice Department will continue to challenge the rulings so far and will attempt to take its challenge directly to a federal court of appeals despite Sullivan's decision Tuesday. In a statement Tuesday, spokesperson Kelly Laco said the department will appeal.
The case "presents important questions that warrant immediate appellate review and is another impractical attempt to disrupt and distract the President from his official duties," Laco said.
In a similar case over Trump's business proceeds that had reached the evidence-collection phase, the Justice Department took the same unusual step to get an appeals court to review the matter.
The appeals court has not yet made a decision in that case, which remains paused.
More than 200 Democratic senators and House members sued Trump in this case. They claim his refusal to present his business holdings to Congress for their approval deprived them of a vote, and his continued business holdings violate the constitutional anti-corruption section known as the Emoluments Clause, which says elected officials cannot collect proceeds from foreign powers.
Sullivan previously signed off on their lawsuit, saying they had the authority to challenge the President and that the legal definition of "emoluments" was broad.
"This extraordinary lawsuit has all the hallmarks of a case worthy of" early review by an appellate court, because it looked at an issue that's never been fully weighed by the courts before, the Justice Department had argued.
But the members of Congress called the early appeal of an appeal a delay tactic built around Trump running for reelection.
"If the President succeeds in running out the clock, an entire presidential term will have gone by with the nation's highest officeholder making countless foreign policy decisions under a cloud of potentially divided loyalty and compromised judgment caused by his enrichment from foreign states. That is precisely the nightmare scenario the Framers adopted the Foreign Emoluments Clause to avoid," the members of Congress wrote in a previous court filing.
On Tuesday, Sen. Richard Blumenthal, a Connecticut Democrat, and Rep. Jerry Nadler, a New York Democrat, issued statements applauding Sullivan's direction to begin evidence collection. "In a thoughtful, well-reasoned opinion, Judge Sullivan articulated what the law makes clear: there is absolutely no reason to delay one more day. ... Today, the courts spoke: no longer."
CNN's Kate Sullivan contributed to this report.