ALBUQUERQUE, N.M. -- New Mexico Gov. Susana Martinez said her office is mulling whether a special legislative session should be held to help the state win Tesla Motors' planned Gigafactory, which will buid batteries.

In a speech to an Albuquerque area commercial real estate development association on Monday, Martinez said her office is evaluating whether a special session is necessary to complete a package of economic incentives being crafted to help make New Mexico more appealing to Tesla, the Albuquerque Journal reported.

"If it's necessary, we are open to whatever we can do that would even include that sort of thing. I've had legislators say, 'If it's necessary, we'll come,'" Martinez said.

New Mexico is one of four states identified as finalists for a lithium-ion battery factory that would supply the company's Fremont assembly plant. Others are Arizona, Nevada and Texas.

Palo Alto-based Tesla says it will invest $2 billion in the 10 million-square-foot factory, which will cost between $4 billion and $5 billion. Its partners will invest the rest.

The new factory will provide enough batteries to supply 500,000 vehicles by 2020, Tesla said. Tesla expects to produce 35,000 vehicles this year.

Martinez wouldn't discuss details of the negotiations with Tesla, but she said New Mexico is in the running for the project in part because of taxation changes that the state has made.

Democratic legislative leaders said a special session to woo Tesla would be unprecedented, and appropriate only if New Mexico has evidence that it was Tesla's pick.

"If there is a possibility of a special session, I believe there's going to have to be some pretty concrete evidence that what we would do here would mean that Tesla would, as a matter of fact, come to New Mexico," said Senate Majority Leader Michael Sanchez, D-Belen.

The House majority whip, Rep. Antonio "Moe" Maestas, D-Albuquerque, who unsuccessfully sponsored legislation during this year's session to provide reduced electricity rates to lure companies such as Tesla, said the Legislature could get a deal done if called upon.

"These are high-level negotiations with the executive branch. If there was some certainty with regard to Tesla's commitment, then I'm confident the Legislature would do what it takes," Maestas said.

Tesla currently sells just one vehicle, the Model S sedan, which starts around $70,000. But it plans to begin making a crossover, the Model X, later this year, and wants to bring a lower cost, mass market vehicle to market in 2017. Tesla said the factory would help lower its battery costs by around 30 percent.