People interfering with critical infrastructure in Manitoba would face tougher fines and possible jail time under legislation introduced Monday.

The Progressive Conservative government says it's fulfilling a promise in last October's Throne Speech to prevent blockades of critical infrastructure and transportation routes.

The bill allows the owner or operator of the infrastructure -- including oil and gas pipelines and provincial highways -- to apply for a court order to create a temporary protection zone.

Violators would face fines of up to $5,000 or up to 30 days in jail.

The Opposition New Democrats say the proposed large fines could be devastating for people who are standing up for their rights.

Justice critic Natalie Fontaine accuses the Tory government of proposing the legislation to silence anyone who doesn't agree with them.

Justice Minister Cameron Friesen says the government is looking for a balance between the rights of people to protest and the need to maintain infrastructure.