The federal environment minister has officially ordered Montreal to halt its plan to dump eight billion litres of raw sewage into the St. Lawrence River.

In an interim order, Leona Aglukkaq said Montreal must not proceed until Nov. 3, to allow a scientific review of the plan.

Earlier in the day, Montreal Mayor Denis Coderre said that delaying the planned dump would be "unreasonable", and neither in the public or environmental interest. The mayor told reporters he hoped the issue could be resolved before Oct. 23.

The ministerial order was enough for Coderre to unequivocally state his position on the federal election, an issue he had skirted around.

"The best thing for Montrealers and for Quebecers, and for people who want to protect the environment, is to get rid of that government," Coderre said at an event for the homeless Friday night.

Coderre said delaying the dump would lead to equipment damage and that waiting past November would mean pushing back the sewage dump until next year.

"All you need to do is to look at the paperwork and I don't even believe that we need an external expert but we are ready to collaborate," said Coderre.

"They wanted that, so OK, they're going to take care of it but they're just playing politics, because they didn't want to have that during the campaign..."

On Wednesday, Aglukkaq said she had "instructed Environment Canada to immediately have an independent expert scientific review of all information related to this project conducted."

Coderre blasted the federal government Wednesday night, saying the government was being "irresponsible."