The Manitoba government is threatening to call in law enforcement if protesters at the Lake St. Martin flood outlet don't back down.

First Nation protesters are camping out at the outlet site, raising concerns about how the structure impacts fishing in the area.

Steve Ashton, the minister responsible for infrastructure and emergency measures, urged the protesters to let crews do their work.

"We will also be looking at other options in terms of contacting law enforcement officials," he told reporters in Winnipeg on Monday.

"I understand people may have issues or concerns. This is about protecting homes … about protecting people."

Ashton said it's not acceptable that the Lake St. Martin outlet has been working at only 80 per cent capacity because of the protest.

"We are committed to resolving any fisheries-related issues, but we need that outlet open in the sense that every day that we don't have the full capacity means less flow," he said.

Ashton said the province did meet with First Nations representatives last week to talk through the issues.