Police officers across Canada can now conduct mandatory alcohol breath tests—a decision that has drawn both praise and concerns.

The legislation, passed by parliament in June ahead of the legalization of cannabis, went into effect Dec. 18.

It means police no longer need to suspect drivers of drinking and driving, though they will still need lawful cause to pull them over.

“They’re going to be demanded to provide sample of breath right off the bat,” EPS Sgt. Robert Davis told CTV News at a check stop in west Edmonton Saturday night. “If someone refuses that demand, they would face the penalties of a criminal refusal charge.”

Drivers that fail the initial screening will undergo further testing at a police station.

It is now also illegal to get behind the wheel within two hours of being over the legal limit.

Mothers Against Drunk Driving Canada supports the stricter laws, arguing mandatory testing will make roads safer.

A local lawyer is concerned that the mandatory screening test is an infringement on the Charter of Rights and Freedoms.

“There’s definitely a couple privacy concerns and I think what we’ll see right away is a challenge of the legislation from a charter perspective,” Lorne Randa, a privacy lawyer at Brownlee LLP, told CTV News. “It’s definitely a step beyond what we’ve seen before with the police powers.”

The new legislation is expected to be challenged in court.

With files from Timm Bruch and The Canadian Press