OAKLAND, Calif. >> City and county officials approved opening negotiations with an investment group on a possible $1.3 billion stadium project that supporters hope will sway the Oakland Raiders to stay.

The approvals Tuesday give an investment team anchored by Hall of Famer Ronnie Lott and former quarterback Rodney Peete the right to negotiate a formal agreement for a $1.3 billion stadium that includes $350 million in public money.

The Alameda County Board of Supervisors voted earlier Tuesday, with the Oakland City Council voting later in the night.

Seven city council members voted to enter negotiations with Lott. One council member abstained. Earlier in the day, three of five county supervisors voted yes after more than three hours of discussion and testimony in a room sparkling with sports celebrities.

Lott said after the county vote that the work is just beginning.

“We still have a long ways to go. We still have to convince the NFL. We still have to convince (Raiders owner) Mark Davis. We’ve got a long ways to go but today is a great day and a great moment for Raider Nation,” he said.

Earlier this year, Mark Davis said he was committed to moving the Raiders to Las Vegas, where a $1.9 billion stadium project has been approved. Oakland Mayor Libby Schaaf vowed to continue working on a counter-proposal for the Raiders to stay at the Oakland Coliseum.

A move to Nevada is not certain, although a vote by the NFL on whether to allow the move is possible as soon as January. Nevada will raise $750 million from a hotel tax to fund the stadium with billionaire casino mogul Sheldon Adelson contributing $650 million and the Raiders and NFL kicking in $500 million.

The Raiders must get approval from 24 of the 32 NFL owners to move. NFL owners will receive an update on the stadium situation when they meet in the Dallas area Wednesday.

The Raiders also have the option of moving to the Los Angeles area, where they can share a facility with the recently relocated Rams.

A spokesman for the Raiders did not return requests for comment.

Former Los Angeles Raiders great Marcus Allen made an emotional pitch to the Alameda County Board of Supervisors and later to the Oakland City Council, saying that losing the team would be devastating for Oakland.

“It would be an emptiness that I don’t think the city could recover from,” he said.

Other speakers urged caution even as they pledged support. They said officials should negotiate jobs and affordable housing for residents in east Oakland where the Coliseum is located, given the soaring cost of housing throughout the city.

A sticking point was that Alameda County and Oakland still need to retire nearly $100 million in debt incurred for remodeling the current stadium to woo the team back from Los Angeles in 1995.

The parties have identified $1.25 billion in potential financing for a project that may cost upward of $1.3 billion for a 55,000-seat stadium that could include mixed-use retail in the future.

Lott’s team, which includes the Fortress Investment Group, would contribute $400 million, with the NFL and the Raiders contributing $500 million.

The city of Oakland would contribute $200 million for infrastructure such as storm drains and roadway parking. The money would be generated from bonds paid back from revenue created from the stadium and its surrounding commercial development.

The city and county would also contribute at least 100 acres of land, valued at $150 million. One of the issues to be determined is whether the land would be sold or leased.

Supervisor Keith Carson grilled a representative of Fortress for details on payment and revenue. He voted no.

Supervisor Wilma Chan abstained. She said at the hearing that while fans have remained loyal, she’s not sure that the Raiders want to stay.

Board President Scott Haggerty joined supervisors Richard Valle and Nate Miley in moving forward, despite the many unknowns.

“What it comes down for me is trust and my mother would trust Ronnie Lott,” he said. “I trust this man and he’s somebody I want to do business with, and I hope he’s somebody Mark Davis wants to do business with.”