Thousands of thrill-seekers who descended on Toronto for the opening of this year's Canadian National Exhibition on Friday morning were greeted by a picket line.

The 140th CNE kicked off at 10 a.m. with a procession of mounted Toronto police and a military band. Both Ontario Premier Doug Ford and Mayor John Tory were on hand. There's also full day of activities planned for those able to make it out.

However an ongoing labour dispute between the board that oversees the Exhibition Grounds and unionized stagehands threatens to put a damper on the late-summer rite of passage for so many in the city.

Members of the International Alliance of Theatrical Stage Employees (IATSE) Local 58, which provides technical and staging expertise for venues at Exhibition Place, have been locked out since July 20. The union has picketed on the Exhibition Grounds and also outside city hall to demand that the board of governors return to the bargaining table.

Union representatives have said that the dispute is primarily over outside contracts. The Exhibition Place board of governors' plan to bring in its own workers to set up and supervise various events while unionized workers have not had a contract since Dec. 2017, representatives said.

So will these pickets from IATSE local 58. Stage hands locked out by Exhibition Place after both sides failed to agree on a new collective agreement <a href="https://t.co/2QnMVYnqHI">pic.twitter.com/2QnMVYnqHI</a> —@LindaWardCBC

Last week, Exhibition Place's negotiating team rejected a proposal for binding arbitration. It also confirmed that the CNE organizers had brought in out-of-province workers from Quebec to set up some venues ahead of opening day.

The enduring labour strife means that those looking for fun on the midway could first have to make way past a picket line.

"We expect that you will encounter some picketers, from IATSE Local 58, at the event. We suggest that you arrive early to the event, to ensure you are through any potential picket line," said Toronto city Coun. Mark Grimes, chair of the Exhibition Place board of governors in a statement.

They say they won’t hold up visitors to <a href="https://twitter.com/LetsGoToTheEX?ref_src=twsrc%5Etfw">@LetsGoToTheEX</a> but will speak with people as they enter. Visitors being advised to give themselves plenty of time. <a href="https://t.co/7RzfXVndSv">pic.twitter.com/7RzfXVndSv</a> —@LindaWardCBC

"Exhibition Place has a full contingency plan in place and remains open for business including venue and site operations. Exhibition Place is working closely with the CNE to ensure it goes ahead, as planned.

Grimes, as well his vice-chair Coun. Justin DiCiano, have said that the union refuses to discuss anything but wage increases, something the union flatly denies.

"We were negotiating in good faith," DiCiano told CBC Radio's Here and Now in an interview on Thursday, adding that the union has actively resisted any attempts to "modernize" its collective agreement.

In his statement, Grimes said the outdated arrangement has left Exhibition Place less competitive.

"At the core of the impasse is the fact that over the last 25 years the lines of business at Exhibition Place have changed to the meetings, convention and exhibition market – with the creation of the Enercare Centre and Beanfield Centre," he said.

"The old Exhibition Stadium was demolished 20 years ago; however we are still working with an antiquated Collective Agreement reflective of the needs from the old stadium days."

Virgina Ludy, CEO of the Canadian National Exhibition, said that the dispute has "created some challenges" for this year's event.

"We would love to have the members of IATSE 58 here doing their work, they're a highly skilled workforce and they are very familiar with our event because they've been providing these services to us for decades. However, the show must go on," Ludy said in an interview early Friday.

She said that the CNE has tried to encourage a more open dialogue between the two sides, and she hopes that the picket doesn't keep some from attending.

"We do realize that there are some folks who do feel very strongly about this and may elect to not come to the Canadian National Exhibition this year. That's unfortunate, because we really do have a phenomenal show this year."