White House chief of staff Mick Mulvaney said Sunday that Democrats will "never" see President Donald Trump's tax returns.

Appearing on "Fox News Sunday," Mulvaney dismissed lawmakers' calls for the returns as pleas for "attention" by way of a "political stunt."

The comment comes just days after Trump dug his heels in again over the returns, telling Democratic lawmakers to deal with his personal lawyers and the attorney general.

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Acting White House chief of staff Mick Mulvaney said Sunday Democrats will "never" see President Donald Trump's tax returns.

"Nor should they," Mulvaney said on "Fox News Sunday." "That's an issue that was already litigated during the election. Voters knew the president could have given his tax returns. They knew that he didn't and they elected him anyway."

Mick Mulvaney says Democrats just want "attention" and are engaging in a "political stunt" after the chairman of the House Ways and Means Committee, Rep. Richard Neal, asked the IRS to provide six years of Trump's personal tax returns and the returns for some of his businesses.

"That is not going to happen and they know it," Mulvaney added.

Last week, Massachusetts Democrat Neal, one of only three congressional officials authorized to request tax returns, set an April 10 deadline for the IRS to turn over Trump's returns.

Read more: Democratic lawmaker asks IRS for 6 years of Trump's tax returns

Mulvaney piled on to his dismissal, saying a "political hit job" does not qualify as a legal base to release the returns.

"They know one of the fundamental principles of the IRS is to protect the confidentiality of you and me and everybody else who files taxes, they know that," Mulvaney said. "They know the terms under law by which the IRS can give them the documents, but political hit job is not one of those reasons."

Trump's attorney Jay Sekulow also dismissed the move, saying on ABC's "This Week" Sunday that the demand pit the IRS as a "political weapon" that would set a dangerous precedent. He warned that congressional lawmakers could target tax returns from figures in the opposite party, such as Republicans to Democratic House Speaker Nancy Pelosi.

Trump broke with precedent when he chose not to release any tax returns as a presidential candidate and doubled down on his refusal last week when he pointed Democratic lawmakers who were concerned about the returns to his personal lawyers and the attorney general.