Quebec's alcohol and gaming board, the Régie des alcools, des courses et des jeux, said it has received four notices opposing the pilot project.
"We know that this has been tried in other countries with not a good success. We're all for having a party city in Montreal, but I think we need to be very cautious about the safety of visitors and residents alike," said Angeliki Souranis, president of Mothers Against Drunk Driving Canada.
Nineteen bars in Montreal's Latin Quarter and Crescent Street area have agreed to take part in the pilot project, which means they will sell alcohol until 5:30 a.m. and shut their doors by 6:00 a.m.
Peter Sergakis, a bar owner and president of the Union of Quebec bar owners, said he's worried about unfair competition.
Sergakis said he thinks it's unfair that only 19 bars — 12 on St-Denis Street and seven on Crescent Street — will be able to collect additional revenue during the peak summer tourist season while hundreds of other establishments will close their doors at 3 a.m.
But downtown bar owners say it's worth a shot to see if the measure can boost business.
"We're trying to get the economy of downtown rejuvenated a little bit so it's not the law yet. It's going to be four weekends. We're going to see if it works. If it does fantastic. If it doesn't, we'll try something else," said Ziggy's Pub owner Ziggy Eichenbaum.
Opponents will be heard by the liquor board before the pilot project is approved.
The first weekend of extended hours is scheduled for June 13. The project will run for four weekends in June and July.