The Cascades Canada plant that makes boxboard at the Toronto port lands will close, throwing 140 out of work, the company announced this week.

Cascades' Norampac division blamed the decision on "unfavourable factors" including higher energy costs and the rising cost of fibre.

But the company also cited high labour costs and said the Commissioners Street plant employees, through their union, had rejected a "labour cost reduction plan" a few weeks ago.

"It was clear from the beginning the consequences if it was not accepted," Genevieve Boyer, Norampac's communications coordinator, said on Thursday.

"The mill was in financial difficulty and has been for a little while now."

A representative from the Communications, Energy and Paperworkers Union said the company had asked for "very severe" salary cuts and other concessions to ensure the plant's survival.

But Norampac would not guarantee job security, "not one day for one worker," if the mill employees agreed, said Bob Huget, CEP Ontario Region vice president, "so obviously we're not interested in entering into these kinds of discussions."

The union wanted to discuss improvements in productivity and other cost-cutting measures at the plant but the company wasn't interested, Huget said. "I'm still hoping that common sense will prevail here."

Boyer said the mill, which makes coated recycled boxboard and has operated in the port lands for three decades, will close indefinitely by September 14 at the latest.

The same day it delivered its news to Toronto employees, Cascades announced it will spend $15 million to improve its tissue plant in Lachute, Quebec. There were vague commitments in the past to improve the Commissioners Street plant, but nothing specific or guaranteed, Huget said.