This story has been updated.

Disabled, elderly, and non-English speaking voters risk disenfranchisement under Texas’ new voting law passed by the GOP-controlled Legislature earlier this year, the U.S. Department of Justice claims in a lawsuit filed Thursday challenging the legislation known as Senate Bill 1.

Signed by Gov. Greg Abbott in September, the legislation further tightened the state’s election laws, with a host of changes including a ban on drive-thru voting and new rules for voting by mail.

While Democrats and voter advocacy groups have attacked SB 1 as a Republican move to suppress turnout in Texas cities — primarily voters of color who tend to lean Democratic — the Justice Department focused its suit on two provisions which it says violate the federal Voting Rights Act and the Civil Rights Act of 1964. One places strict limits on how much assistance can be given to voters who, because of disabilities or limited English proficiency, may need help navigating the voting process. The second places new constraints on how people who vote by mail verify their identities.

The suit, filed in San Antonio federal court, argues that both provisions”will curtail fundamental voting rights without advancing any legitimate state interest.”

“These vulnerable voters already confront barriers to the ballot box, and SB 1 will exacerbate the challenges they face in exercising their fundamental right to vote,” the suit argues, saying that the law would negatively impact voters with disabilities, elderly voters, members of the military who are deployed, voters with limited English proficiency, and voters residing outside of the country.

The state has long allowed voters who need assistance casting ballots to have someone help them, as long as those assisting don’t try to influence the actual votes. SB 1 places new constraints on what those assistants may do. They cannot answer questions, clarify translations, explain the voting process, or paraphrase complex language, the federal lawsuit says.

The law also creates potential criminal penalties for people who assist voters. A person assisting a voter is required to fill out paperwork disclosing their relationship to that voter. They must also recite an expanded oath — now under the penalty of perjury — that states they did not “pressure or coerce” the voter into picking them for assistance.

The oath no longer allows explicitly answering the voter’s questions. Instead, an assistant must pledge to limit their assistance to “reading the ballot to the voter, directing the voter to read the ballot, marking the voter’s ballot, or directing the voter to mark the ballot.”

The limits on assistance will hit particularly hard voters with limited English proficiency and those with disabilities, the lawsuit contends.

“There is a history of discrimination against voters with disabilities in Texas,” the lawsuit claims, noting estimates that 28% of Texans have conditions impairing their mobility, cognition, or vision.

The suit also takes aim at SB 1’s new rules for mail-in voting. Texas traditionally has placed more limits on mail-in voting than other states. The legitimacy of mail-in ballots was largely determined by comparing signatures on applications and ballots.

SB 1 created new ID requirements. Voters who want to be mailed a ballot must provide their driver’s license number or, if they don’t have one, the last four digits of their Social Security number when they send in an application for one.

They then must provide the same numbers on the envelope used to return their completed ballot. Critics point out that many voters — particularly elderly applicants — may have their votes thrown out simply because they didn’t remember which ID number they used the first time, or have lost their ID card.

The law, set to take effect in time for the 2022 primary elections, already faced legal challenges that generally argue it will disproportionately impact voters of color and voters with disabilities. Those challenges, along with Thursday’s lawsuit, could delay its implementation.

Abbott, in a tweet responding to news of the suit, defended the new law, saying, “Bring it … In Texas it is easier to vote but harder to cheat.”

Texas House Democrats applauded the Justice Department’s move, saying they were “grateful … for taking decisive action to stop Texas Republicans’ continued attacks on our democracy.”

“Senate Bill 1 is a sweeping piece of legislation that creates unnecessary and deliberate barriers to voting,” said a statement from state Reps. Chris TurnerRafael AnchíaNicole Collier, and Garnet Coleman, a group of Democrats who chair the House Democratic Caucus, Mexican American Legislative Caucus, Texas Legislative Black Caucus and Legislative Study Group, respectively.

The group also reiterated its call on Congress to pass federal voting legislation, which was part of what fueled a weeks-long quorum break from most House Democrats over the summer in an effort to block passage of the GOP elections bill.

This article originally appeared in The Texas Tribune, a nonpartisan, nonprofit media organization that informs Texans — and engages with them — about public policy, politics, government, and statewide issues.

Cassandra Pollock, The Texas Tribune

Cassandra Pollock is The Texas Tribune’s state politics reporter. She joined the Tribune full-time in June 2017 after a fellowship during the 85th Texas Legislature.