WASHINGTON (Reuters) - The Democratic head of a powerful U.S. House committee asked the Internal Revenue Service for six years of President Donald Trump’s personal and business tax returns on Wednesday, in a long-awaited move widely expected to lead to a long court battle with the White House.

The request, in a letter from Ways and Means Committee Chairman Richard Neal to IRS Commissioner Charles Rettig, is viewed by Democrats in the House of Representatives as a vital first step toward oversight of Trump’s income taxes and business network, which some lawmakers believe could be rife with conflicts of interest and potential tax law violations.

“It is critical to ensure the accountability of our government and elected officials. To maintain trust in our democracy, the American people must be assured that their government is operating properly, as laws intend,” Neal said in a statement.

IRS and U.S. Treasury officials were not immediately available for comment.

Trump defied decades of precedent as a presidential candidate by refusing to release the tax documents and has continued to keep them under wraps as president, saying his returns were “under audit” by the IRS.

Trump’s former personal lawyer Michael Cohen recently testified in Congress that he did not believe the president was being audited but may have used the audit claim to avoid scrutiny that could lead to an audit and IRS tax penalties.

Trump was dismissive of the request but continued to make the audit argument in comments to reporters during a meeting with U.S. military leaders on Wednesday.

“Is that all?” the president asked when told Democrats wanted to see six years of his returns.

“Usually it’s 10, so I guess they’re giving up,” he said. “I’ve been under audit for many years because the numbers are big and I guess when you have a name, you’re audited. But until such time as I’m not under audit, I would not be inclined to do that.”

House Ways and Means Committee Chairman Richard Neal discusses his request to IRS Commissioner Charles Rettig for copies of President Donald Trump's tax returns as he talks to reporters at the U.S. Capitol in Washington, U.S., April 4, 2019. REUTERS/Yuri Gripas

Neal based his request on his committee’s oversight jurisdiction of the IRS, specifically its alleged audits of Trump and the extent to which the agency has enforced the tax laws against the president.

OVERSIGHT PRESSURE

Congressional Republicans oppose Neal’s effort, saying such a move sets a dangerous precedent by turning the confidential tax documents of a U.S. citizen into a political weapon.

“This particular request is an abuse of the tax-writing committees’ statutory authority and violates the intent and safeguards of ... the Internal Revenue Code,” Representative Kevin Brady, the committee’s top Republican, said in a statement.

Independent analysts welcomed the move.

“The Ways and Means Committee’s strongest oversight ability is making sure the IRS is operating properly,” said Steve Rosenthal, a senior fellow at the nonpartisan Tax Policy Center think tank in Washington.

It was the third time this week a Democratic-led House committee exerted oversight pressure on Trump. Earlier on Wednesday, the House Judiciary Committee authorized its chairman to subpoena Special Counsel Robert Mueller’s full investigation report on Russia’s role in the 2016 U.S. election.

The House Oversight Committee subpoenaed a former White House security chief on Tuesday.

Neal’s committee initially planned to request only Trump’s personal tax returns. But some Democrats and independent analysts pressed for them to include business returns to better gauge the president’s activity in the private sector.

The request includes returns for eight entities: Donald J Trump Revocable Trust, DJT Holdings LLC, DJT Holdings Managing Member LLC, DTTM Operations LLC, DTTM Operations Managing Member Corp, LFB Acquisition Member Corp, LFB Acquisition LLC and Trump National Golf Club.

A Democratic aide said the committee selected a manageable number of business entities that provide a vital window on Trump’s business activity.

Although Trump has never released his returns, the New York Times last year cited a “vast trove” of returns and financial records saying it showed he engaged in tax schemes including cases of fraud in which he and his siblings helped their parents dodge millions of dollars in taxes. The White House called the report misleading.