A clean air activist said Thursday that a new refinery might not be built in Saint John if there were a tighter deadline on reducing greenhouse gas emissions.

The federal government's Clean Air Act, tabled in the House of Commons Thursday, would begin regulating smog levels by 2020 and would cut greenhouse gas emissions in half by 2050.

Gordon Dalzell, spokesman for the Saint John Clean Air Coalition, said the Irvings might reconsider their plan to build a new refinery if the target for reducing emissions weren't so far in the future.

"If this legislation had introduced a strict cap on these emissions, let's say in one year, I'd kind of wonder if this refinery would ever be built," said Dalzell.

"A second refinery that emits the amount of pollution that the current one does would never be able to keep within the cap."

Irving Oil won't make a final decision on building a new refinery until 2007.

Jennifer Parker, spokeswoman for Irving Oil, said it's too early to speculate about how the proposed Clean Air Act might affect the company's plans to develop a second refinery. But she said that a new refinery would meet all environmental regulations.

"If we decide to put a second refinery here, and if we move ahead with permitting, you can count on it being one of the cleanest and best refineries in the world, from the standpoint of environmental performance," she said.