WASHINGTON – President Donald Trump said Wednesday he will not authorize the release of his tax returns, likely setting up a major legal battle over whether Congress can review his financial records.

"I’m not gonna do it while I’m under audit," Trump told reporters at the White House, though congressional Democrats said the law does entitle them to review tax records.

The Internal Revenue Service faces a congressional deadline Wednesday on whether to comply with a request for Trump's records from the House Ways and Means Committee.

In an April 3 letter to the IRS, Rep. Richard Neal, D-Mass, the committee chairman, cited a law allowing Congress to review individual tax returns for legislative purposes. His committee, Neal wrote, is "considering legislative proposals and conducting oversight related to our Federal tax laws."

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Trump said Democrats are digging for dirt, even though "my finances are very clean."

The president has said for years he would not release his taxes because they are under audit, but that is not a legal requirement; he could release his returns whether they were under audit or not.

If the IRS follows through and refuses Congress' request for Trump taxes, the House Ways and Means Committee may consider a subpoena for them. Trump aides, meanwhile, have indicated they are willing to go to court to test whether lawmakers have the constitutional right to review individual returns.

Trump's lawyer, William Consovoy, sent the IRS a letter objecting to any release, saying Trump's returns should be protected by privacy.

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"This request is a transparent effort by one political party to harass an official from the other party because they dislike his politics and speech," Consovoy wrote in his letter.

Defying tradition, Trump refused to release his returns during his 2016 presidential campaign, and has maintained his defiance since moving into the White House.

Trump spoke about his taxes Wednesday before leaving on a Texas trip devoted mostly to politics.

In addition to fundraisers in San Antonio and Houston, Trump meets with a group of engineers to sign an executive order designed to make it easier for energy companies to develop pipelines and other projects. The order also limits the ability of state governments to intervene and hold up projects because of environmental concerns.

The president is expected to sign the order while meeting with the International Union of Operating Engineers at their education center near Houston.