Stricter impaired driving laws are set to come into force next week.

When Bill C-46 kicks in on Dec. 18, police will be able to demand a breathalyzer test from any driver pulled over for violating traffic laws or at a check stop.

"The problem we face right now is many impaired drivers are not that easily detected and, in some instances, may not even show obvious signs of intoxication — at least while they're sitting in the driver's seat of their vehicle," RCMP Supt. Gary Graham said at a news conference in Edmonton Monday.

Under the current law, officers must have reasonable grounds to suspect a driver is impaired to demand a breathalyzer test.

Under the new mandatory alcohol screening provisions, police will be able to demand a breath sample from a driver immediately, without having to have reasonable grounds to suspect the driver is impaired.

"It's very unintrusive, very quick. Two minutes later and you're gone," said Sgt. Brent Robinson, an impaired driving specialist with Alberta RCMP.

But some criminal defence lawyers warned the bill violates charter protections against unreasonable searches and will be deemed unconstitutional by the courts.

The Senate amended the bill earlier this year to remove the provision allowing police to demand a breathalyzer test without reasonable grounds, but it was rejected by the House of Commons.

Earlier this month, Justice Minister Jody Wilson-Raybould conceded the law will likely be challenged in court, but said she is "100 per cent confident" it does not violate the Charter of Rights and Freedoms.

The government cites authorities in Ireland who credit mandatory screening laws for reducing the number of road deaths by roughly 40 per cent in the first four years after it was enacted in that country. Mandatory alcohol screening is the law in several other countries, including Australia, New Zealand and Denmark.

On Dec. 1, Alberta RCMP participated in a nationwide impaired driving enforcement day. Nearly 12,000 cars were checked, leading to 23 charges of alcohol impaired driving and two drug impaired driving charges.

"We all need to work together so that everyone gets home safely," said Graham.