A B.C. judge has given the government until the end of June to make changes to a section of the province's tough drunk-driving law that has been declared unconstitutional.

Last month, Justice Jon Sigurdson ruled that immediate 90-day driving penalty, fines and costs issued to people who blow over .08 in roadside tests are not "demonstrably justified in a free and democratic society."

The B.C. Supreme Court judge issued another ruling Friday, giving the government six months' grace time to get rid of the offending part of the law. It will officially become invalid on June 30, 2012.

"I have concluded that an immediate declaration of invalidity of part of the [automatic roadside prohibition] regime may pose a danger to the public," Sigurdson explained in his decision.

He added that the unconstitutional section can simply be chopped from the legislation, while the rest of the tough penalties brought in last year can remain as they are.

The province says that until the law is fixed, drivers who blow over .08 will be charged under the Criminal Code and can still face a 90-day driving prohibition.

In a statement, Attorney General Shirley Bond said that she was "appreciative" of the extra time to come up with a solution.

"We will work to introduce changes to the Motor Vehicle Act as soon as possible in the spring legislative session. We continue to analyze Justice Sigurdson's comprehensive decision to determine what those changes will consist of," she said.

"We are not going to give up our fight to remove impaired drivers from B.C.'s roads, and we will continue to use every responsible tool at our disposal to combat drinking and driving."

Thousands of British Columbians who were penalized under the impugned law are hoping to ask for compensation from the government as well as the return of the money they were forced to pay for fines, towing, mandatory driver education and ignition-locking devices. A proposed class action lawsuit seeking just that and spearheaded by Kirstyn Louise Nobbs was filed in B.C. Supreme Court Friday.

Sigurdson wrote in his decision that he does not yet have enough information to decide that matter and asked for more submissions from lawyers on both sides.

The judge's ruling also cleared up some confusion about the roadside penalties doled out to people who refuse breathalyzer tests. He wrote that those punishments are constitutional and will be allowed to stand.

Sigurdson has already ruled that the penalties for those who blow in the "warn" range of .05 to .08 are acceptable.

The province has touted a 40-per-cent decrease in alcohol-related driving deaths in the year since the complete law was brought in and heralded as the toughest in Canada.

From Oct. 1, 2010 to Sept. 30, 2011 there were 68 alcohol-related driving deaths in the province – 45 fewer than B.C.'s five-year average of 113.

During that period, police served more than 23,300 roadside prohibitions and impounded more than 20,000 alleged drunk drivers' vehicles.