Neal said that the Committee is "considering legislative proposals and conducting oversight related to our Federal tax laws, including, but not limited to, the extent to which the IRS audits and enforces the Federal tax laws against a President".
US federal law clearly details that when the chairman of the US House Ways and Means Committee provides a request in writing for any US citizen's tax returns - even a sitting US president - the US Treasury, now headed by Trump appointee Steve Mnuchin, "shall furnish" the documents.
Neil also dismissed concerns regarding the request, which were raised by Treasury Secretary Steve Mnuchin.
Trump declined to provide his tax information as a candidate in 2016 and as president, something party nominees have traditionally done in the name of the transparency.
Neal argued in this second letter that the law granting him the authority to request tax documents is "Unambiguous and raises no complicated legal issues that warrant supervision or review by" the Justice or Treasury Departments.
Democrats have made clear that their best chance at defeating President Donald Trump in 2020 is by winning back three states Trump narrowly captured: Wisconsin, Michigan and Pennsylvania. He claimed - and has continued to claim - that he could not make his tax returns public because they were under audit by the IRS.
Neal asked the IRS last Wednesday to turn over six years of the president's tax returns within a week.
The response by Rep. Richard Neal, the House Ways and Means Committee chairman, comes after the administration asked for more time to consider his initial request last week.
Trump had told reporters before Mnuchin sent the letter that he "would love to give" the returns, but would not do so while he was under audit, a stand he long has taken.
Mnuchin said that Treasury Department lawyers have been working "diligently" to research the issues involved and have been in contact with Justice Department attorneys.
A top House Democrat is ratcheting up his demand for access to President Donald Trump's tax returns, telling the IRS that the law clearly gives Congress a right to them.
If Rettig fails to respond, Neal says that'll be interpreted as denying the request, which could pave the way for a court battle.
Constitutionally, Neal has the power to demand the IRS release tax returns for any United States individual.
"For good reason, it would be a gross abuse of power for the majority to use tax returns as a weapon to attack, harass, and intimidate their political opponents".