RICHMOND — Virginia's General Assembly passed measures Friday to broaden access to absentee voting in this fall's presidential election, including the creation of ballot drop boxes that Republicans warned would be an invitation to fraud.

Democrats used their control of both chambers to muscle through the bills, arguing that concerns about voting during a pandemic and a time of uncertainty around the U.S. Postal Service called for extraordinary action.

Each measure would set aside $2 million for prepaid postage on mail-in ballots and instruct registrars to allow voters to correct ballot errors that might keep an absentee vote from being counted. The bills also would remove the requirement for a witness to certify a ballot signature and mandate drop boxes at voting precincts as an alternative to putting absentee ballots in the mail.

Once the Senate and House of Delegates take up each other’s version, the matter will go to Gov. Ralph Northam (D) — who supports the legislation — for his signature.

“What this bill aims to do is to keep voters safe from the coronavirus when they are exercising their right to vote,” said Sen. Janet D. Howell (D-Fairfax), who sponsored the Senate version.

Republican senators zeroed in on the drop boxes during two days of debate, arguing that they would allow partisan groups to “harvest ballots” from those who are homebound or in nursing homes under the guise of taking them in bulk to a drop box.

“For the first time, we lose the chain of custody between a voter and the ballot box,” Sen. Stephen D. Newman (R-Bedford) said during preliminary debate on Thursday. Without changes, he said, “we are going to have fraud in the election.”

Newman proposed changing the bill to require that an absentee ballot be put into the collection box “by the voter.” When Democrats pointed out that the proposal would undercut the idea of protecting infirm or disabled people from exposure to the novel coronavirus, Newman offered to specify that family members or caregivers could deposit a ballot.

But Democrats resisted, saying ballots would be secure because they have to be signed by the voter and sealed, and that each ballot carries a unique bar code that allows it to be tracked.

“Having the voter decide how to return the ballot is key,” said Sen. Adam P. Ebbin (D-Alexandria). “I don’t see fraud coming.”

As debate continued on Friday, Sen. John S. Edwards (D-Roanoke) added that there are no such restrictions placed on mail-in ballots. “Anybody can take it to the mailbox, too,” he said

Drop boxes have become a national issue in the run-up to the Nov. 3 election. States are seeing a surge of interest in absentee voting as a way to avoid crowded polling places during the pandemic, but the Postal Service has warned states of possible delays with mailed ballots. Drop boxes allow voters to return their ballots without mailing them.

President Trump, who has admitted slowing funding to the Postal Service to try to restrict mail-in voting, has derided drop boxes on Twitter. “So who is going to ‘collect’ the Ballots, and what might be done to them prior to tabulation? A Rigged Election? So bad for our Country,” he tweeted earlier this month.

Alabama is the only state that requires a voter to personally mail or return an absentee ballot, while 26 states and D.C. allow a voter to designate someone to return their absentee ballot, according to the National Conference of State Legislatures. Another 10 states permit a family member to return a ballot, and 13 don’t address the issue, according to the NCSL.

Northam called for expanded absentee voting measures in a budget proposal he submitted before the start of the General Assembly’s special session, which convened Aug. 18.

Because of concerns about the pandemic, the Senate is meeting in a large conference room at the Science Museum of Virginia and the House is holding a virtual session.

On Friday, Democrats defended the voting plan as secure. It calls on local registrars to set up drop boxes at their offices, as well as any satellite voting offices and at polling precincts on Election Day. Registrars can also put the boxes at other locations if they deem it necessary.

The state Department of Elections would be charged with establishing security procedures, including surveillance cameras and daily ballot collections by workers from both major parties.

House Republicans had challenged the drop box plan in a committee hearing earlier in the week but on Friday focused on a different aspect of the legislation: the $2 million set aside for return postage on mailed ballots.

Noting that the state is working to address a $2.7 billion shortfall in its two-year budget, Del. Kirk Cox (R-Colonial Heights) said paying for postage is an unnecessary expense.

“If you take this to its logical conclusion, we should be giving gas cards for people to drive to their polling place,” Cox said during the House session. In an interview later, he added that the package of changes was being rushed into place at the last minute.

“I don’t think it helps people having confidence in the elections,” he said.

But Democrats said it is the Trump administration undermining confidence in the election, with Postmaster General Louis DeJoy calling for cuts to services and Trump stirring fears of fraud.

“We have taken steps today to ensure we protect Virginians’ sacred voting rights from interference — whether from a pandemic or the Postmaster General,” House Speaker Eileen Filler-Corn (D-Fairfax) said in an emailed statement.