HARRISBURG — Pennsylvania voters will be asked for photo identification at polling places in the April 24 primary election, but won’t be barred from casting ballots if they don’t produce it.

The statewide balloting is being used for a test run of the new law that — starting in the Nov. 6 general election — will require Pennsylvanians to show a photo ID that meets state guidelines every time they vote. The goal is to educate voters and identify problems so officials can try to eliminate them before the much larger voter turnout anticipated for the presidential election.

The law Gov. Tom Corbett signed last month following an intensely partisan debate put Pennsylvania among a handful of states with the strictest voter ID requirements amid ongoing GOP efforts in legislatures across the country to toughen such laws.

Republicans who advocated the law portray it as an effort to curb voter fraud, even though they cannot cite examples of such fraud. Democratic critics charge that it is a thinly veiled effort to suppress the vote for President Barack Obama in a key battleground state in the fall election and argued that it would discriminate against elderly, poor and minority voters.

The American Civil Liberties Union has vowed to challenge the Pennsylvania law in court. Last month, similar laws were blocked in Texas by the U.S. Justice Department and ruled unconstitutional by state judges in Wisconsin.

In the primary, poll workers will ask voters for an acceptable form of identification — a Pennsylvania driver’s license, for example — but allow registered voters to cast ballots whether or not they have it. Leaflets describing the new requirement and how to comply will be handed out at the polls.

“Our plan is to give them out to everyone, whether they have ID or not,” said Shari Brewer, the director of elections in Butler County. “We want to keep it as simple as possible for this election.”

The law allows Pennsylvania driver’s licenses to be used as an ID for voting purposes up to one year past the expiration date, but it requires all other photo IDs to contain a future expiration date.

In the general election, voters who do not have proper identification will be allowed to cast provisional ballots that will be counted if they provide a valid ID to county election officials within six days. They also can apply for a free photo identification card through PennDOT.

The law has alarmed students at some of Pennsylvania’s largest schools, including Penn State, Temple and the 14 state-owned universities, because their IDs do not have expiration dates and many students do not have a Pennsylvania driver’s license. The Morning Call in Allentown, which was first to report the story, said stickers bearing an expiration date were among the remedies being considered.

Some county officials predict the dress rehearsal of the new law will delay primary balloting. Lines at polling places were not uncommon even under the prior law, which required identification only from people voting in a district for the first time and did not require photo IDs.

In July, state officials plan to launch a $3 million-plus informational campaign — financed by federal funds — that will include newspaper, TV and radio ads as well as robo-calls. In September, literature will be mailed to every household with a voter, said Secretary of State Carol Aichele.

“It is our intent to make sure every eligible voter in Pennsylvania has a photo ID,” said Aichele, the state’s top elections official.