UPDATE:A strike has been averted.

Art Gallery of Ontario staff are prepared to strike at midnight Thursday night if contract negotiations fail to produce a new deal.

Union members planned to picket the Dundas St. W. entrance of the gallery at 5 p.m. Thursday, which could disrupt the gallery’s popular monthly “First Thursdays” event, in which the AGO throws open its doors to the public with a partylike atmosphere amid its galleries. The event is widely regarded as a huge success in drawing new audiences.

Heather Corner, a representative of the Ontario Public Service Employees Union, which represents some 463 full- and part-time gallery staff across all departments, said union members would picket just hours before First Thursday is set to open.

“We’re looking for support and to provide information,” she said. The union set the deadline after two months of talks with the gallery failed to yield an agreement.

“We’re pretty far apart on some major points,” said Corner. The union’s main issue, she says, is the gallery’s reduction of full-time unionized staff, whether by layoff or voluntary separation, and their replacement with contract or part-time workers.

Caitlin Coull, the gallery’s communications manager, wrote in an emailed statement that the AGO is “making tough choices in a complex and challenging environment; we are taking action that will balance the need for long-term sustainability and fairness to our employees. We are confident that the offer is appropriate in the current environment.” Of the picket, she wrote that “we respect the right of our employees to communicate in a lawful manner.”

Last year, the gallery offered buyouts to staff, which 10 people took. Since November, when the last contract expired, seven staff members have been laid off, either in the gallery’s food and beverage department or building maintenance.

In 2011, a similar midnight deadline was extended several times through the night until a deal was reached by noon the following day. Corner said the same was possible this time.

However, if the union walked out at midnight, it would leave management and security staff, who are not part of the union, to clean up after the crowd of revellers, which staff typically does after First Thursday to 3 a.m. or later. “It could be pretty messy,” she said.