New federal legislation that virtually abolishes a “two-beer” defence to an impaired driving charge is being pulled into court for a legal spot check.

Before the new legislation took effect last July 2, people accused of driving with more than .08 milligrams of alcohol in 100 millilitres of blood — particularly if they were only marginally over the limit — would often argue they had consumed just two beers. They might also say they drank the last one not long before the breath test, which could have resulted in more alcohol in their breath than in their blood.

Under the new changes, part of the federal government’s Tackling Violent Crime Act, accused people who want to challenge a breathalyzer result are now required to provide the court with technical evidence proving the equipment was malfunctioning or wasn’t operated properly.

The first step in the legal challenge begins today when defence lawyers and the Crown appear in the Superior Court of Justice in Toronto for arguments over which level of court should hear the challenge.

Law professor Alan Young and defence lawyer Joseph Neuberger, represents three men charged with having unlawful blood alcohol levels.

Young and Neuberger believe the legislation is unconstitutional because it no longer permits them to raise reasonable doubt about the validity of a breathalyzer result by calling evidence about their clients’ pattern of alcohol consumption.

“The particulars of the breath machines, including maintenance records, specs and the manufacturer’s manual are shrouded in secrecy, withheld by the Crown and the manufacturer,” Neuberger said.