WINSTON-SALEM, N.C. (Reuters) - Minority voters in North Carolina will have a harder time casting a ballot this presidential election year if a judge allows a law requiring photo identification at the polls to take effect, challengers of the law said in federal court on Monday.

Flyers informing voters of the new voter ID law that will go into effect for the 2016 election are seen at the Mecklenburg County Board of Elections warehouse in Charlotte, North Carolina November 3, 2014. REUTERS/Chris Keane

But a lawyer representing the state said only a small number of people may not have the necessary forms of identification and exceptions will be allowed under an amended version of the measure.

“It’s a policy question,” lawyer Thomas Farr said. “The evidence here does not rise anywhere close to showing a discriminatory intent.”

The trial in Winston-Salem is one of several closely watched voting rights battles that will play out across the country as Democrats and Republicans fight for the White House in November.

Democrats argue voter ID laws passed by Republican-led state legislatures target voters who typically support the Democratic party. Proponents of the measures say they are intended to prevent voter fraud.

The case in North Carolina tests a key piece of broad voting restrictions passed soon after the U.S. Supreme Court ruled in 2013 that states with a history of discrimination no longer needed federal approval for voting law changes affecting minorities.

The U.S. Justice Department and National Association for the Advancement of Colored People argue North Carolina’s revised voting protocol disproportionately burdens African-Americans and Hispanics, who are more likely than whites to lack the acceptable forms of identification.

The law “threatens to deter, confuse and disenfranchise voters,” said Michael Glick, a lawyer representing the NAACP. “It sets out to solve a problem that never existed.”

Last summer, U.S. District Judge Thomas Schroeder heard arguments about the state’s decision to shorten its early voting period, end same-day registration, eliminate pre-registration for 16- and 17-year-olds and stop provisional ballots cast outside the correct precinct from being counted. He has not issued a decision.

The voter ID requirement is getting a separate vetting after lawmakers amended it in 2015 ahead of the initial trial.

Now voters who cite a “reasonable impediment” to being able to obtain acceptable identification will be allowed to cast a provisional ballot. South Carolina is the only other state with a reasonable impediment provision, Farr said.

Challengers said the law remains discriminatory and could give election workers too much discretion.

It is unknown if Schroeder will rule before the state’s presidential primaries in March.