She said it will be business as usual for the Hastings tannery until April 1, when the contract expires.
Sproston said it was a case of waiting to see what would happen, but losing that much of the firm's business was obviously a big blow.
Sproston said she was surprised to not have been contacted directly yet by any Graeme Lowe Tannery staff.
"I think the way the times are at the moment, they may have expected it, I'm not too sure," she said.
"It's really sad because there are workers that have been at Graeme Lowe Tannery a long time. But they can rest assured that we'll be with them every step of the way."
E tū has 17 members working at the tannery.
Lowe Corporation and Silver Fern Farms have both been approached for comment.