LANSING, Mich. — The Michigan Senate voted Wednesday to facilitate a deal to replace a contentious 65-year-old oil pipeline in the Great Lakes, approving legislation to empower a new authority to oversee the construction and operation of a utility tunnel that would encase the new pipeline.

The bill, approved on a 25-13 mostly party-line vote in the Republican-controlled chamber, was sent to the House for consideration next. It would create the three-member Mackinac Straights Corridor Authority to handle functions related to building the tunnel, which supporters say would better protect against a potential spill.

Outgoing GOP Gov. Rick Snyder — who would appoint the initial members of the authority — is working on several fronts to finalize an October agreement with Canadian oil transport giant Enbridge to replace the underwater segment of its Line 5, which carries about 23 million gallons of oil and natural gas liquids daily between Superior, Wisconsin, and Sarnia, Ontario. A more than 4-mile-long section, divided into two pipes, lies on the floor of the churning Straits of Mackinac, the convergence of Lakes Huron and Michigan.

The massive engineering project is expected to take seven to 10 years to complete, at a cost of $350 million to $500 million — all of which the company would pay. Opponents of the deal say oil and liquids used to make propane should not continue flowing daily through the lines.

Democratic Gov.-elect Gretchen Whitmer pledged during her campaign to shut down Line 5 and criticized the tunnel plan, as did fellow Democrat Dana Nessel, who won the race for attorney general. Both take office in January and have said the Snyder administration should not steamroll the plan to enactment in the meantime.

Republican Sen. Wayne Schmidt of Traverse City, whose district includes the pipeline, said the goal is to protect the Straits while making sure “energy is affordable, reliable and accessible. … By doing a utility corridor, that is the absolutely safest way to do that.” Sen. Adam Hollier of Detroit, the lone Democrat to support the legislation , said it would ensure “people are taken care of in the winter” and also provide work for laborers who build the tunnel.

Opponents, however, continued to criticize the bill, which was changed to no longer have the existing Mackinac Bridge Authority help to enable the tunnel agreement.

“This rushed, half-baked legislation to advance the Snyder/Enbridge tunnel scheme is a diversion from the real issue that Michigan simply doesn’t need Line 5,” Mike Shriberg, Great Lakes regional executive director of the National Wildlife Federation, said in a statement. “The legislation attempts to keep the existing Line 5 threatening our water, economy and way of life for at least another decade while ignoring the safer alternatives for meeting Michigan’s energy needs. That’s a good deal for Enbridge and their lobbyists at the Capitol. It’s a bad deal for Michigan.”