The fate of Texas' controversial new voter ID law - which requires voters to show photo identification at the polls - is set to be decided this week in a federal court in Washington.

The state, which claims the law will prevent voter fraud, is seeking to persuade a three-judge panel to uphold the statute. The Justice Department and a slew of intervening groups say the law disproportionately affects minority voters, violating the federal Voting Rights Act. They want it thrown out.

The case will be a test of the Voting Rights Act, passed in 1965, which was designed to protect minorities' rights to vote.

The Justice Department set up this week's court fight when it blocked implementation of the law in March. Texas quickly filed a lawsuit in federal court, bringing the two sides back to Washington for the second time in months.

The two sides spent two weeks earlier this year arguing in front of a similar three-judge panel about Texas' redrawn congressional maps. As now, the Justice Department claimed Texas was violating the federal Voting Rights Act. No final decision has been made in that case, but a federal court has approved interim maps that have allowed Texas elections to go ahead.