Alameda is set for a bitter breakup today with the Orange County developer that hoped to build a 12,000-resident community at the former Naval Air Station.

The city manager has recommended that the City Council end its ties with SunCal, the company that has been working on the project for four years. If the council agrees, SunCal will be the second master developer to have failed to build at the 1,500-acre former base, which has largely languished since the Navy left in 1996.

"We think this plan creates a lot of risks for the city, and there was a lack of commitment on behalf of the developer," Deputy City Manager Jennifer Ott said. "Of course we're disappointed, but we would have liked a really detailed, substantial analysis, which they never provided."

SunCal has spent about $12 million on research and public outreach for the plan, which calls for 4,800 homes, a 60-acre sports complex, 140 acres of parks, a ferry terminal and about 4 million square feet of commercial space.

The city manager's recommendation is unfair, SunCal officials said Monday.

"We've been wronged," said SunCal vice president of operations Pat Keliher. "We've done everything they've asked us to do. If this does not go through, we will not walk away quietly."

Relations between Alameda and SunCal haven't always been this strained. The city chose SunCal in 2007 to build a mix of housing, parks, industry, offices and shops at the base, which is a 15-minute ferry ride from San Francisco and offers spectacular views of the bay and East Bay hills.

After dozens of community meetings, SunCal presented a plan by renowned urban planner Peter Calthorpe that, at first, the City Council and many city residents seemed to support. The hitch was that it included multiunit housing, which violated a 1973 law banning anything larger than a duplex on the island city.

As SunCal prepared to let the voters decide, relations with the city staff members and council began to dissolve over some of the details, such as the amount of affordable housing and the cost of the proposed schools, fire station, library and other amenities.

Mayor Beverly Johnson and Councilman Frank Matarrese both withdrew their support in the months leading up to the February election. SunCal's ballot measure lost by 85 percent.

In the current economy, no development at the base is financially viable without multiunit housing, SunCal officials said.

So SunCal is now seeking the city's permission to use state affordable housing incentives to circumvent Alameda's multiunit housing ban. That request is on the council's agenda for today.

"This deal is worth billions of dollars, but it's our future. It's the biggest issue we'll face," Matarrese said. "We need to do what we can to keep the city solvent, safe and functional."

Any development at Alameda Point needs to focus on job creation, not housing, Matarrese and others said. SunCal should have been more aggressive in finding tenants and analyzing the businesses that could relocate there, Matarrese said.

Some in Alameda said SunCal's plan is the city's best chance at securing a mixed-use development for the former base, which has slipped into disrepair since the Navy left and needs $600 million in infrastructure improvements.

"We've got to get out of the Dark Ages," said Ron Matthews, head of the Alameda Little League and Alameda High School Boosters. "We desperately need parks and playfields for our kids, and this gives us that. I think this would be absolutely great for Alameda."