The Western Fair District's move to expand its Saturday farmer's market to Sunday isn't sitting well with some vendors, including some who say the move will mean an end to their business because working Sunday goes against their religious beliefs.

In June, the Western Fair Association announced plans to add a Sunday market operating from 10 a.m. to 3 p.m. to the traditional Saturday market, which operates from 8 a.m. to 3 p.m.

The Sunday market is slated to start on Oct. 6. Vendors have been told that opening on Sundays will be mandatory.

Some vendors who spoke to CBC News said the expansion will force them into a difficult transition.

For nine years, butcher Calvin Kuepfer has made the 90-minute drive from his farm in Wellesley, Ont., to sell his sausage and beef cuts at the market, where sales represent 60 per cent of his overall business, Country Style Meats.

He's done well at the market but now his equipment is for sale because as a devout Mennonite, Kuepfer cannot work Sundays. He said some of the market's Amish vendors are in the same position.

"I'm going out of business because of this," said Kuepfer.

More vendors speak out

Monika Michel of M&R Orchards is also unhappy with the Sunday expansion. She and her husband are at the market every Saturday, where they sell apples and cider from their orchard near Tillsonburg.

She said the mandatory Sunday opening would leave the 60-year-old grandmother with no time to rest after working to harvest apples and bottle cider for market.

"We work five days on the farm to grow this stuff and pack this stuff, getting ready for market," she said.

"Now they want us to do a Sunday market. When do we have time to recharge our batteries? Never," she added.

Calls from CBC News to the Western Fair District were not returned Monday evening.

Sunday openings will be mandatory

Particularly galling for Michel is that vendors weren't given the option of staying open on Saturdays only, she said. She was told if she didn't open Sundays her booth could be assigned to another vendor willing to open both days.

"They can terminate me with 30-day notice," she said.

The Sunday expansion was billed a chance to meet a rising demand and spread the crowds out over two days. The Fair Association also has plans to spend $400,000 in upgrades to the 90-year-old brick building that houses the market.

But Steve Hillier is worried in making that transition, the market — which he calls "a gem" of London's Old East Village — may be losing its roots.

Hillier was a founding vendor at the market with his Canada Comfort Foods booth, where he sold baked goods. Health problems forced him to sell his business two years ago, but he still works with many of the existing vendors, helping them with online marketing and social media.

He said vendors are worried that adding a second day will split the same number of customers over two days, increasing their costs without adding much to their bottom line.

"They're nervous," said Hillier. "I'm very sad for the religious people, because they're the ones that built this place."

For some vendors, Sunday is a 'golden opportunity'

Jo Rivas is one vendor who's happy with The Market's plans to expand to Sundays. She's closing True Taco's Dundas Street location to focus on her booth at The Market. (Andrew Lupton/CBC)

Not every vendor who spoke to CBC News thinks the Sunday expansion is a bad idea.

Jo Rivas owns True Taco and operates a booth in the market on Saturday. Up until this week, she also ran a storefront restaurant on Dundas Street.

She's now closing the storefront in part because she feels the Sunday hours will be a bigger boost to her business.

"It's actually a golden opportunity for us, we're very happy to have an extra day," she said. "We feel bad for some of the vendors ... but it's such a big building it's a shame that it isn't open the rest of the week."

Chris DeVries owns Common Ground Farm, which sells farm fresh produce at the market. He understands the concerns of some vendors, but said it's worth waiting to see how Sunday sales go.

He also said the transition was well communicated to vendors.

"They've been very open with us about their intention to add a second day," said DeVries. "If in the long run it brings in more sales then it's worth it."

You can listen to the interview below.