WASHINGTON (AP) — President Donald Trump is scoffing at Democrats' attempts to pry loose his tax returns, saying his refusal to release the records as a candidate didn't hurt him in 2016 and voters "didn't care" about the issue.

A leading House Democrat has issued subpoenas for six years of Trump's tax documents and given Treasury Secretary Steven Mnuchin and IRS Commissioner Charles Rettig a deadline of this coming Friday to deliver them.

Trump has privately made clear he has no intention of turning over the much-coveted material. He is the first president since Watergate to decline to make his returns public, often claiming that he would release them if he were not under audit.

The subpoenas came from Rep. Richard Neal, chairman of the House Ways and Means Committee, on Friday, days after Mnuchin refused to comply with demands to turn over Trump's returns. Mnuchin said the committee's request "lacks a legitimate legislative purpose," as Supreme Court precedent requires.

Neal, D-Mass., reminded the two Trump appointees in a letter that federal law states that the IRS "shall furnish" the tax returns of any individual upon the request of the chairmen of Congress' tax-writing committees and that his committee "has never been denied" a request.

Trump tweeted on Saturday that he won in 2016 "partially based on no Tax Returns while I am under audit (which I still am), and the voters didn't care. Now the Radical Left Democrats want to again relitigate this matter. Make it a part of the 2020 Election!"

The White House and the Democratic-controlled House are battling over investigations into Trump, and the administration has refused to comply with subpoenas for the unredacted report by special counsel Robert Mueller and documents related to the testimony by former White House counsel Donald McGahn.

If Mnuchin and Rettig fail to heed the latest demand from Neal, he is likely to sue in federal court.

Neal, who first demanded access to Trump's tax returns in early April, maintains that the committee is looking into the effectiveness of IRS mandatory audits of tax returns of all sitting presidents — a way to justify his claim that the committee has a potential legislative purpose. Democrats are confident in their legal justification and say Trump is stalling in an attempt to delay the issue beyond the 2020 election.

In rejecting Neal's request, Mnuchin said he relied on the advice of the Justice Department. He concluded that the Treasury Department is "not authorized to disclose the requested returns and return information." Mnuchin has also said that Neal's request had the potential to make private tax returns a political matter.

Republicans say Neal is using the arcane 1924 law that empowers him to obtain any individual's tax filing to play politics with Trump. Democrats also want to probe into Trump's business dealings, particularly his business relationships with foreigners and to see who he owes money to.