TORONTO -- An ongoing labour dispute that has led to picket lines outside the Canadian National Exhibition could result in the popular Toronto fair losing about $1.5 million this year, according to the CEO of the annual event.

The CNE, which draws large crowds to its shows, rides and edible offerings, is underway at Exhibition Place, where the venue's board of governors locked out about 400 stagehands and technical employees on July 20.

The head of the CNE said the dispute is discouraging ticket sales, and said she decided to voice her concerns in a letter to Toronto's mayor and councillors as they held a special meeting about the situation on Tuesday. Exhibition Place's board is made up of a mayor's designate, four council members and four public appointees, according to its website.

"We are a tenant here on the grounds so we thought it was important to let the councillors and the mayor know the preliminary impacts of the lockout," Virginia Ludy said in a phone interview on Wednesday.

"We would like them to get back to the table and start negotiating because they have not been at the table since the lockout started."

Ludy said the CNE expects significant loss in revenue and increased expenses that were not budgeted for as a result of the dispute.

"We have had to do enhanced security, we have had to allocate housing and food services for the folks who are doing the work, and we have had to get legal services," she said, referring to out-of-province workers brought in by Exhibition Place's board of governors to work at the CNE.

The board's vice-chair, however, took issue with the CNE's linking its estimated financial losses primarily to the labour dispute.

"How is the strike affecting (the CNE) more than the torrential downpours that are happening since the day they opened," said Coun. Justin Di Ciano.

"I would say to the leadership of the CNE to be very careful when you start talking like that unless you want to give us a proof. And even if there is a proof, we are in a lockout situation to make things better for everybody."

The board has said it wants to update the locked-out employees' contract to reflect what it called the "highly competitive" marketplace.

IATSE Local 58, the union representing the workers, said the employees have been without a contract since December 2017, and will be walking picket lines through the duration of the CNE.

Local president Justin Antheunis said workers have received considerable support, but called it "bittersweet."

"It is great that we have all this support and that people are recognizing how unfair the city is to these workers," he said. "But it does not make us feel good that the CNE, a 140-year-old institution, is suffering."

Antheunis said he has not heard back from Exhibition Place's board of governors for more than a month and added that he hopes to get back to the negotiating table soon.

Toronto Mayor John Tory has said all sides want to ensure the CNE is successful.

The event, founded in 1879, is one of the largest fairs in North America and will run until Sept. 3.