HARRISBURG — Pennsylvania’s highest court on Tuesday told a lower court judge to stop a tough new law requiring voters to show photo identification from taking effect in this year’s presidential election if he finds voters cannot easily get ID cards or if he thinks they will be disenfranchised.

The 4-2 decision by the state Supreme Court sends the case back to a Commonwealth Court judge who initially said the divisive law could go forward. The high court asked the judge, Robert Simpson, for his opinion by Oct. 2.

If Simpson finds there will be no voter disenfranchisement and that IDs are easily obtained, then the 6-month-old law can stand, the Supreme Court said.

“It’s certainly a very positive step in the right direction in that the court recognizes that the state does not make adequate provision for people to get the ID that they would need to vote,” said David Gersch, the lead lawyer for the plaintiffs challenging the law’s constitutionality. “In addition, there is a practical problem with getting the ID to people in the short time available.”

A spokesman for the Pennsylvania Department of State, which oversees voting and elections, said the agency will provide whatever information that Simpson may seek.