Central Maine Power is facing tough competition in a $1 billion bid to build a transmission line from Canada through Maine and held a news conference Wednesday to challenge its rivals and assert itself as the cheapest and most-reliable choice to supply Massachusetts with hydroelectricity.

The event took place in Augusta, and was attended by Maine business leaders and municipal supporters. But the message was meant for New England media, which joined via conference call.

The takeaway was: CMP’s project will save Massachusetts electric customers $600 million over two competing proposals – Northern Pass in New Hampshire and the New England Clean Power Link in Vermont.

“We have great momentum,” said Sara Burns, CMP’s president, who ticked off the advantages of the company’s New England Clean Energy Connect project.

Burns was joined by Bob Kump, CEO of CMP’s parent company, Avangrid Networks.

“The New England Clean Energy Connect will deliver up to 20 percent more clean energy for the region’s utility customers with lower construction costs than any of the competing proposals that are interconnecting with Hydro-Québec,” Kump said.

CMP-Avangrid’s claims were immediately contested by Martin Murray, manager for Eversource Media Relations in New Hampshire and a spokesman for Northern Pass.

“Northern Pass is the most mature project available,” Murray said. “By being in service fully two years prior to CMP or any other conceptual project, Northern Pass will deliver hundreds of millions of additional dollars in benefits to Massachusetts consumers and earlier progress toward achieving clean-energy goals.”

Murray added that Northern Pass already has fully executed contracts with all major contractors and suppliers, and labor agreements with union workers in Massachusetts and New Hampshire.

But neither Northern Pass or CMP mentioned the fact that large transmission projects can face public opposition, and Northern Pass already has been delayed for years over concerns about overhead lines running through scenic areas. The project now vows to bury 60 miles underground.

In Maine, Burns said the CMP project has been met with support in towns along the corridor. At Wednesday’s event, she said she wasn’t aware of any organized opposition.

But anti-wind activists who see the project as also having the potential to connect new wind farms in the western Maine mountains are set to fight it, if it’s approved.

“This project does nothing good for Maine – it’s being built for Massachusetts utilities and shareholders of Avangrid/CMP,” said Richard McDonald, president of Saving Maine. “Destroying tens of thousands of acres of pristine landscape for corporate profit is the bottom line for this project – Maine gets used again.”

Tuesday’s conflicting statements reflect the fact that a multibillion dollar competition is approaching a key deadline.

Massachusetts passed a law last year requiring the state to seek long-term contracts for offshore wind farms and land-based renewable energy. The law calls for 1,600 megawatts of wind energy and 1,200 megawatts from other sources, such as hydro, land-based wind and solar.

A megawatt of generating capacity provides enough energy to serve between 750 and 1,000 homes.

Dozens of bids were submitted from across New England and eastern Canada, including a handful of other proposals from Maine. Initial land-based winners are scheduled to be announced on Jan. 25.

Initial winners will be asked to submit long-term contracts in April. All projects will have to clear extensive environmental and regulatory reviews, as well as public hearings.

But only one project involving Hydro-Quebec will be chosen, so the three competitors are trying to stand out.

“This is really going to come down to, how many megawatt hours can you deliver at what price, and can you get your line permitted,” said Jeremy Payne, executive director of the Maine Renewable Energy Association. “But everybody is looking to get ahead. And CMP-Avangrid isn’t immune to the optics of showing the benefits they’ll bring to ratepayers.”

The other competitors also are trying to make a public case for why they’re the best choice.

In Western Massachusetts, the New England Clean Power Link announced that if it wins the contract, it will give $1 million a year over 20 years to help upgrade the energy efficiency of low-income homes. The lead sponsor, Transmission Developers Inc., plans to lay a high-voltage transmission cable under Lake Champlain in Vermont to carry up to 1,000 megawatts to the Bay State.

In New Hampshire, Northern Pass is holding “job and supplier fairs” in December and January, meant to showcase the jobs, subcontractor opportunities and supplies needed to complete the 192-mile line, designed to carry 1,090 megawatts.

A news release this week said Northern Pass representatives will discuss the project’s business directory, a list of local services available to the project’s many workers, including restaurants, gas stations and hotels. It noted that the U.S. Department of Energy recently issued a Presidential Permit for cross-border construction.

Murray said other permits are expected to be in hand by April, making Northern Pass “the only project that will be ‘shovel ready’ early in the second quarter of 2018.”

Both Northern Pass and the Clean Energy Link have stated costs of $1.6 billion.

CMP-Avangrid announced Wednesday that it can do its project for $950 million. That would save Massachusetts electric customers more than $600 million over the reported costs of the two competitors, which are as much as 60 percent higher.

During the news event, Burns was asked why she was announcing the figures now, since decision-makers in Massachusetts already know them. Burns replied that she’s often asked about the cost and decided it was time to release it publicly.

Until now, CMP had indicated that the cost was confidential. But in fact, Burns confirmed to the Portland Press Herald in July, when the company first announced the project, that the cost would be in the $1 billion range.

When a reporter asked if her strategy was to put pressure on evaluators in Massachusetts, Burns said it had become clear from what competitors were saying that CMP should talk about its advantages.

The CMP-Avangrid bid is a 145-mile line that would follow a corridor it already owns, from Beattie Township, on the Canadian border north of Route 27 and Coburn Gore, through Farmington and Jay to Lewiston, where it would connect to the regional electric grid at an upgraded substation.

The project will make fuller use of CMP’s recently completed Maine Power Reliability Program, a $1.4 billion power grid infrastructure investment paid for by ratepayers from across New England. That project proves CMP’s ability to build a line of this scale on time and on budget, Burns said.

The total cost would be paid by Massachusetts electric customers. Maine would benefit from construction jobs, added tax revenue and anticipated savings on wholesale energy costs over the 20-year life of the power contract.

It’s also possible that a similar line, being proposed by CMP and NextEra Energy in the clean-energy bidding, could carry power from new solar and energy-storage projects in western Maine, as well as wind turbines on both sides of the border.