ABC NewsBy ALLISON PECORIN and TRISH TURNER, ABC News

(WASHINGTON) -- Dr. Anthony Fauci will warn of "needless suffering and death" if states reopen too soon when he testifies before the Senate Tuesday, according to an email he sent the New York Times.

“If we skip over the checkpoints in the guidelines to ‘Open America Again,’ then we risk the danger of multiple outbreaks throughout the country. This will not only result in needless suffering and death, but would actually set us back on our quest to return to normal,” the nation's top infectious disease expert said in the email ahead of his first testimony since mid-March, referring to the White House plan to reopen the economy.

Democrats are eager to question him without President Donald Trump standing nearby.

"This will be one of the first opportunities for Dr. Fauci to tell the American people the unvarnished truth without the president lurking over his shoulder," Senate Minority Leader Chuck Schumer said Monday about what could be a blockbuster hearing. "Dr. Fauci, let it rip."

Over the last month, Trump has been encouraging some states to begin opening up commerce and some other non-essential businesses to kick start the ailing economy amid record high unemployment, but Democrats have criticized the administration for doing so without -- what they referred to as -- a roadmap guided by science.

Fauci, along with other top health care officials, who serve on the White House coronavirus task force and are self-quarantining after potential COVID-19 exposures, are scheduled to appear via videoconference before a Senate committee Tuesday to answer questions about re-opening the country.

Besides Fauci, director of the National Institute of Allergy and Infectious Diseases, Centers for Disease Control and Prevention Director Robert Redfield, Food and Drug Administration Commissioner Steven Hahn and White House "testing czar" Adm. Brett Giroir will testify before the Senate Health, Education, Labor and Pensions Committee Tuesday morning.

While many committee members plan to also appear remotely -- which could blunt spirited questioning -- fireworks are expected nonetheless.

The hearing came together under controversial circumstances. The White House refused to let Fauci appear before a committee hearing chaired by Democrats in the House. Then, Trump announced that he would waive his moratorium on testimony by administration officials during the pandemic, allowing the group of senior officials to appear before the committee chaired by Sen. Lamar Alexander, R-Tenn. The move sparked outrage among Democrats.

Democrats plan to drill down on recent reports that the administration shelved re-opening guidelines that had been approved by the CDC.

The document, which gave detailed guidance to help business owners and state authorities begin to open their doors, was reportedly kept from publication by the Trump administration. The White House denied that the draft was finalized, and Dr. Deborah Birx, the coronavirus response coordinator, told CNN on Thursday that "no one stopped" the guidelines from being released and that they're still being edited.

"We can't expect people to go back to work, or restaurants, or confidently send their kids to school, if there isn't clear, detailed guidance about how to do that safely," said Sen. Patty Murray, D-Wash., according to an advanced copy of her opening remarks. "We need to make sure industries across the country know how to safely reopen, and that people know their workplaces are safe."

Alexander said this weekend that he believes that the economy must reopen but that a robust testing strategy would be required to do it.

"The only solution is test, trace, isolate, treatments and vaccines," the committee chairman said in an NBC interview on Sunday. "We have to reopen the economy. We have to do it carefully. We have to let people go back to work and earn a living."

Alexander and Sen. Roy Blunt, R-Mo., who chairs a key appropriations subcommittee, secured funding in the $2 trillion COVID-19 relief package for a "shark tank" competition to speed the quality and availability of tests around the country.

The urgency for testing is shared by Murray, though the Democrat has gone further by calling on the administration to implement a national testing strategy by May 24, as is required by the $2 trillion coronavirus relief package that passed in March.

The Trump administration responded to this requirement in April by issuing an eight-page testing "blueprint" for states, though the administration has maintained that testing strategies should fall largely to individual states. Democrats have called that approach inadequate.

In a letter to the White House last week, Democratic senators called the lack of detail in the president's blueprint "deeply troubling" and said a more comprehensive plan would be required to fulfill the requirements outlined in the relief package.

"States need more than vague musings from the White House," Murray said of testing during a hearing Thursday. "They actually need numbers and timelines and clear expectations of how the federal government is going to get us there."

But Giroir maintained on Monday that anyone who needs a test can get a test in a Rose Garden news conference.

And when asked Monday by ABC News Chief White House correspondent Jonathan Karl about when Americans across the country could expect to get tested every day as they go back to work, Trump said "very soon."

"We are testing. We have great capability. You look at all of these machines here, they're incredible machines -- the best anywhere in the world," Trump said.

A recent ABC News survey found that, absent a national testing strategy, many states have been left with a patchwork of testing systems, while some still struggle to access necessary testing supplies.

Sen. Chris Murphy, D-Conn., on Thursday questioned the president's motives in not developing a detailed national testing plan and instead leaving it to governors.

"From the beginning the president hasn't wanted to know the true extent of the virus. He doesn't want to do a national testing plan," Murphy said. "We aren't going to get one unless the president make it a priority let's just be clear he's not."

Other lawmakers are expected to focus their line of questioning on the task force itself, and their perception that some members have caved to the will of the president. Sen. Bernie Sanders, I-Vt., said he thinks Fauci is doing a great job, but questioned other members of the team.

"I would hope that all of those who are around the president, who understand science, have the courage to speak up and do the right thing," Sanders said. "But clearly he has an intimidating impact not only on his task force, but on the entire United States Senate and the Republican leadership there. What we need now is a call for morality and a call for science -- how do you open up the economy in a way that is safe?"

Also likely to be brought up during Tuesday's hearing is a bi-partisan push -- led by Sen. Susan Collins, R-Maine, and Sen. Bob Menendez, D-N.J. -- to increase funding for state and local governments that have had their budgets depleted by the coronavirus.

Collins, a panel member, has defied the White House and her own leadership in pushing for this aid that the president has, so far, not supported. Senate Majority Leader Mitch McConnell took heat for suggesting that states could file for bankruptcy, but has since backed off saying that aid might be approved so long as it is not spent on problems that existed before the pandemic, like near-bankrupt state pension plans.

Committee members are also expected to focus on the status of vaccines, contact tracing and how to safely reopen more businesses and schools at reduced capacity.

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