WASHINGTON – Democrats and liberal advocates plan to use the annual tax filing deadline as a showcase to demand the release of President Donald Trump's tax returns and to call for more electronic tax filing, as Republicans focus on a legislative overhaul.

Thousands of people are expected at the U.S. Capitol on Saturday, the traditional April 15 filing deadline, to protest Trump's refusal to release his tax information. Similar events will be held across the country and in the United Kingdom, Germany, Japan and New Zealand.

Liberal activists are the organizers, backed by more than 70 progressive groups such as MoveOn.org.

"We march to demand that the president release his returns, as he has repeatedly promised, but failed, to do. We march because it is in the best interest of the American people to know what financial entanglements and conflicts of interest our leaders have," says the website for what's known as Tax March.

This year's filing deadline is Tuesday because April 15 falls on a Saturday and Monday is a legal holiday, Emancipation Day, in the nation's capital.

More than 100.9 million tax returns have been processed as of April 7, according to the IRS, and more than 80.2 million refunds totaling $228.9 billion have been issued.

Staging rallies to promote tax cuts or other issues before Tax Day has long been a staple in the GOP playbook. But several senior House and Senate aides said there were no plans — with lawmakers in the middle of a two-week spring break — for party leaders to stage high-profile national events that would tie Tax Day to the GOP's ambitious agenda for slashing tax rates and streamlining the tax code.

Emily Schillinger, a Ways and Means Committee spokeswoman, said its chairman, Rep. Kevin Brady, R-Texas, is "making the case for progrowth tax reform in his district" during the congressional recess and plans a tele-town hall on tax issues on Monday.

AshLee Strong, a spokeswoman for House Speaker Paul Ryan, R-Wis., said that Republican leaders are stressing the need for a tax plan during the congressional break.

Saturday's marches will use large inflated white roosters with golden pompadour-shaped combs — custom-made for the Chinese lunar year of the rooster — as props to a make the case for the release of Trump's tax returns.

Trump initially said during the 2016 campaign that he would release his tax returns, but reversed course and said he couldn't because he was being audited.

He is the first president since Gerald Ford not to release his tax information. Now that he's president, Trump and Vice President Mike Pence will have all of their tax returns audited while they hold these offices because of an IRS rule that's been in place since President Richard Nixon's tenure.

Rep. Bill Pascrell, D-N.J., said he plans to attend the event in Newark, N.J., to promote his resolution that directs Treasury Secretary Steven Mnuchin to release Trump's returns for the last 10 years. He said he believes that Republicans were shying away from Tax Day events.

"How can you talk about tax reform without knowing where the president stands on these things and without releasing his tax returns?" Pascrell asked.

Some Democrats, such as Sen. Elizabeth Warren of Massachusetts, are linking the tax filing deadline to reviving a bill that would require the IRS to develop a free online tax preparation and filing service.

Sen. Jeanne Shaheen, D-N.H., said that it would be a "common-sense solution to make Tax Day easier."

David Burton, a senior fellow at the Heritage Foundation, a conservative think tank, said that the Republican Party's muted approach to the tax-filing deadline this year stands in contrast to past events when copies of the tax code were used as props in mock funerals or dropped into Boston Harbor.

Burton noted there was a dearth of scheduled Tax Day events among Republicans to promote a tax overhaul, which he attributed to "limited bandwidth" of conservative advocacy groups and to intraparty disputes about the House GOP proposal for border adjustments that would tax imports and exempt exports.

"There's a lot less conservative or libertarian grass roots efforts — that I know of — promoting tax reform. Part of it may be differences over border tax adjustments," he said.

Former Rep. Phil English, R-Pa., voiced concern that Republicans were not holding events to promote a tax overhaul ahead of the filing deadline. When he served in Congress, English hosted events that included shredding the tax code with a chain-saw.

"If Democrats are making more hay out of Tax Day than Republicans, you know there is not only a messaging shortage, there is a terrible dysfunction in the coalition," he said.

Despite some intraparty disputes on tax issues, English and Burton said they remained hopeful that Trump and GOP leaders would rally support for a big tax bill.

"There is still time to generate support for tax reform," Burton said.