TORONTO -- Ontarians were urged to stock up on booze over the weekend ahead of a possible strike by liquor store workers that could begin before Canada Day.

The Liquor Control Board of Ontario and the union representing its employees said they planned to negotiate around the clock ahead of the strike deadline set at 12:01 a.m. Monday, but both sides said consumers, bars and restaurants would be wise to make their purchases this weekend, just in case.

"The strike deadline falls at one of the busiest times of the year when customers are planning activities with family and friends over the Canada Day long weekend," the LCBO said in a statement.

"To ensure access to the best product selection and to avoid longer than normal checkout lines, we encourage customers to shop as far in advance of Sunday, June 25 as possible."

The LCBO said it had extended store hours -- detailed on its website -- so customers could get their shopping done.

In the event of a labour disruption, the LCBO said it is planning to provide some level of service across the province.

But Smokey Thomas, president of the Ontario Public Service Employees Union, said he believed the LCBO would have trouble stocking any stores it keeps open because unionized workers control the warehouses.

"There would be some booze kicking around for a while, but it would run out," he said.

Thomas said there are four possible scenarios come Monday -- a deal is reached, the union strikes, the LCBO locks out employees, or both sides agree to extend negotiations past the strike deadline because an agreement is within reach.

Both sides said they're optimistic a deal can be reached before the deadline.

The 8,000 unionized LCBO workers, who have been without a contract since March 31, voted 93 per cent in favour of a strike in April.