Actor Martin Sheen smiles as he joins the strikers outside the Fairmont Royal York Hotel in downtown Toronto. (CBC)

Workers at the Fairmont Royal York Hotel launched a 24-hour strike as the Toronto International Film Festival entered its first weekend.

Union members began picketing at Front and York streets at 7 a.m. ET Friday although the actual strike action began seven hours earlier.

Members of Unite Here Local 75, representing 900 employees at the Fairmont, said their patience had run out with the hotel's owners. Their hope was that the one-day walkout will pressure the company to return to negotiations.

The union has said the hotel has been asking for concessions while reaping the benefits of increased business from events such as the film festival, which began Thursday and ends Sept. 19.

At one point, actor Martin Sheen, who was staying in the hotel, joined the picket line and put on a striker's placard.

"If you want us to leave the hotel, I've spoken to all the actors staying here — including my son Emilio — we are ready to walk if you give us the word," Sheen said.

The actor shook hands with one striker, who spoke to him in Spanish. Someone in the crowd shouted, "Mr. Martin, God bless you!"

Sheen said the workers chose a good time to make their point. He said as a longtime union member he understands their concerns.

Workers, whose contract expired July 16, say they've been dealing with increased workloads, cutbacks and shortened shifts.

The union said 86 per cent of the workers who voted Wednesday cast ballots in favour of a strike.

Arley DaSaliva, a banquet server at the hotel for the past 10 years, said he's mindful of the strike's timing.

"TIFF is very important for us, and we realize that TIFF is important for the city, too," he said. The workers don't want to interrupt the event, but it's time they earned some respect, he said.

Hotel spokesperson Melanie Coates told CBC News that management was ready to talk with the union.

"We will get to an agreement as we have over the past six years. I'm confident that will happen soon," Coates said.

'Welcome to Toronto'

Strikers handed out pamphlets headlined, "Dear Film Festival Visitors: Welcome to Toronto!"

The pamphlet says the workers are proud of the city and the event, but a "quiet crisis" has hotels keeping staffing levels too low, under-employing some and overworking others.

Limited-duration strikes are possible at "several" Toronto-area hotels in the coming days, but workers will not demand that guests check out, the pamphlet says.

Union employees at the Hyatt, a central hub for this year's TIFF, held a one-day walkout on Sept. 3 because they are trying to get a contract.

Local 75 represents more than 7,000 hotel, hospitality and gaming workers in the Greater Toronto Area.

With files from The Canadian Press