OKLAHOMA CITY — The Oklahoma Supreme Court has blocked a new drunken-driving law from taking effect.

An order handed down by the state’s highest court Monday prevents the Impaired Driving Elimination Act from taking effect as scheduled on Wednesday and prohibits authorities from enforcing its provisions until the court rules on a lawsuit challenging its constitutionality.

The law creates a new program for first-time DUI offenders and abolishes the appeals process for people trying to keep their licenses after being arrested for DUI. It was approved by the Legislature earlier this year and was supported by Mothers Against Drunk Driving.

But a lawsuit filed in June by four attorneys alleges the law is unconstitutional. Among other things, the lawsuit alleges it denies a person the right to due process.