The denial is not a surprise. The Trump administration already turned down Neal's April request for six years of tax information about the President's personal and business finances.

But, the disregard for the subpoena brings into sharper focus the eventual court fight and raises questions about what Neal might do next.

The Ways and Means Chairman said he was consulting with counsel about "moving forward."

"Issuance of these subpoenas should not have been necessary," Neal said in a statement Friday evening. "The law provides clear statutory authority for the Chair of the Ways and Means Committee to request and receive access to tax returns and return information. The law, by its terms, does not allow for discretion as to whether to comply with a request for tax returns and return information."

"I don't see what good it would do at this particular time," Neal said Friday before the Mnuchin's announcement about holding the Treasury Department or IRS Commissioner Charles Rettig Rettig in contempt. "I think if both sides have made up their minds, better to move it to the next branch of government, the judiciary."

Neal could go to court to both enforce the subpoena and to enforce IRS statute 6103, which says the House Ways and Means Committee Chairman can request any individual's tax return information and the Treasury of the Secretary "shall furnish" it.

Moving directly to court wouldn't follow the typical pattern for subpoena fights, however. In the past, those court battles between the executive and Congress, chairmen have first moved to go hold officials in contempt for not cooperating before going to a judge. That was the case when the House Oversight Committee went to court to obtain documents related to the gun-walking scandal known as Fast and Furious in 2012. Harriet Miers, a former White House Counsel for President George W. Bush, was also held in contempt for not testifying before the House sued to enforce the subpoena.

"I support moving forward with contempt I support using the inherent power this Congress has whether it is by fine or confinement to use that power and let this administration know that we have a credible alternative," said Texas Democratic Rep. Lloyd Doggett, who also sits on the Ways and Means Committee. "As long as they think we will be timid about this, they will push the limits and Trump will continue grabbing more and more power."

But despite pressure from some in his left flank, Neal has continued to shy away from a public confrontation with Treasury Secretary Steve Mnuchin. Instead, Neal -- who waited decades for the gavel of the powerful tax-writing committee -- has continued to focus on goals he shares with the administration including priorities like infrastructure. Neal told CNN Friday he has closely followed the advice of House counsel.

"I think following the advice of counsel is where I'm going to end up," Neal said Friday.

If he were to move directly to court, Neal would have two options. Either the entire House of Representatives could vote to authorize litigation or the BLAG -- the Bipartisan Legal Action Group made up of the top five House leaders -- could vote. Democrats hold a three-to-two advantage on the BLAG and would have enough votes to send the case to court.

The Treasury Department has argued that Neal does not have a legitimate legislative purpose in his fight for the tax return, a refrain the Trump administration and the President's personal lawyers have invoked on numerous document requests from House Democrats. But, Neal has said he is looking to understand how the presidential audit program works.

Once an individual comes into the White House, the IRS does an audit, but Neal has argued that the scope of that audit or the fallout from it is not clear. In order to potentially enshrine it in law, Neal has said he needs to see the President's tax returns.

This story has been updated with additional developments Friday.