Democratic presidential hopeful Jay Inslee called for the closure of an oil and gas pipeline running across the Great Lakes, calling the pipeline and a proposed replacement tunnel a “clear and present threat” to the environment.

The Washington governor has made addressing climate change the central message of his campaign for the Democratic Party’s nomination for president. Inslee slammed the 66-year-old pipeline in a statement Wednesday.

“They threaten the clean drinking water that millions depend upon,” Inslee said. “And they would lock in decades of climate pollution that we can’t afford. ... This dangerous pipeline must be decommissioned, the proposed oil tunnel must not be built and clean alternatives must be explored immediately.”

Inslee backed up his statements on Twitter, saying the “dangerous” pipeline must be decommissioned and the proposed tunnel should not be built.

Fossil fuel infrastructure is dirty, dangerous, and poses a threat to our communities. Today, I’m announcing my opposition to the Enbridge Line 5 pipeline in Michigan and the proposed tunnel to replace it. https://t.co/IxDz8jcbfG — Jay Inslee (@JayInslee) July 10, 2019

Inslee said the pipeline should be “a major topic” in the upcoming Democratic primary debate in Detroit. He called on his fellow presidential candidates to oppose the Enbridge plan.

Inslee’s campaign struggled to gain traction in the crowded Democratic field, but has sought to stand out by presenting a comprehensive plan to reduce fossil fuel use and encourage clean building practices. Inslee said his climate plan is the most robust and effective agenda during a visit to neighborhoods affected by urban pollution in Detroit.

Inslee’s ambitious “100% Clean Energy for America Plan” lays out clean energy standards for new vehicles, public infrastructure and the construction of new buildings.

As president, Inslee said he would use executive action to push some policies through a divided Congress. Inslee said his plan would create 8 million jobs, particularly in manufacturing cities like Detroit.

Enbridge’s Line 5 pipeline spans 645 miles between Superior, Wisconsin, and Sarnia, Ontario, carrying 23 million gallons of crude oil and natural gas liquids per day.

The contested area is a 4-mile segment divided into dual pipes that extend across the Straits of Mackinac, linking Lake Huron and Lake Michigan.

Enbridge representatives have repeatedly said the pipeline is in sound condition, but environmental activists worry a leak would be catastrophic for the Great Lakes.

Enbridge reached a deal last year with then-Republican Gov. Rick Snyder to decommission the twin underwater pipes and replace them with a single pipe housed in a tunnel built in bedrock beneath the straits.

The idea remains controversial for environmentalists and some Democrats in the state Legislature, who would prefer no oil be transported across the straits at all. Republican lawmakers say there is no other alternative to satisfy the demand for energy, and closing the pipeline would cost thousands of jobs.

Democratic Gov. Gretchen Whitmer, who rode a blue wave in Michigan to replace the term-limited Snyder in January, has long opposed the current pipeline. Whitmer tried to negotiate a faster timetable for the tunnel project, but talks with Enbridge broke down.

Whitmer ordered the Department of Natural Resources to review violations of the easement granting Line 5 the ability to operate.

“The governor’s primary goal has always been and remains to get the Line 5 dual pipelines out of the Straits of Mackinac as soon as possible," said Whitmer Administration Press Secretary Tiffany Brown. “The risk of a catastrophic oil spill in the Great Lakes, and the harm that would follow to Michigan’s economy, tourism, and our way of life, is far too great to allow the pipelines to continue to operate indefinitely.”

Democratic Attorney General Dana Nessel filed a civil lawsuit last month, asking the Ingham County Circuit Court to shut the pipeline down.

The National Wildlife Federation said Nessel acted to protect Michigan’s citizens, businesses and communities.

The NWF remains distrustful of Enbridge, in part due to its role in the 2010 oil spill on the Kalamazoo River, the most onshore costly spill in American history. According to a release from NWF, Enbridge paid more than $187 million in penalties and settlements due to environmental and business practice violations.

Other environmental groups praised Inslee for drawing national attention to the issue.

The Michigan League of Conservation Voters called on all presidential candidates to join Inslee in demanding the shutdown. The pipeline puts the Great Lakes at risk every day, said Executive Director Lisa Wozniak.

“Line 5 is a relic of the past,” she said. "It is imperative that we embrace a clean energy future – such as wind, solar and new technologies – to rapidly make us more energy independent and make the current controversy around Line 5 irrelevant.”

Kate Madigan, director of the Michigan Climate Action Network, said protecting the Great Lakes from an oil spill should be a top priority for Michigan and the country.

“Building an oil tunnel to replace Line 5 is an outdated solution that does not take seriously the mounting scientific warnings and the worsening climate impacts that we are now experiencing,” she said.

Enbridge spokesman Ryan Duffy told the AP that the company is committed to moving ahead with the tunnel project. Enbridge said the project would reduce the risk of a leak in the Straits of Mackinac to “virtually zero” and be completed by 2024.

“The tunnel solution is the best long-term opportunity to secure the energy needs of the state while making an already safe pipeline even safer,” Duffy said.