High-end hybrid carmaker Fisker Automotive has stopped work at its Delaware Project Nina plant and laid off 66 workers, and is renegotiating its $529 million Department of Energy loan amidst news that it has been blocked from accessing the money since May.

It’s bad news for Fisker on top of bad news that’s been filtering out for months. The Anaheim, Calif.-based startup has continually delayed the sale of its Fisker Karma plug-in hybrid sports car. That’s hurt lithium-ion battery maker and partner A123 Systems, which laid off about 125 employees in November and lowered its annual revenue forecast, a move blamed largely on Fisker’s delays.

At the same time, Fisker has been renovating an old General Motors plant to build its next-generation “Project Nina” lower-cost plug-in hybrid sedans. That’s the reason it won a $529 million AVTM loan in 2010, and the project it has now halted as it seeks to renegotiate its loan. 

So far, Fisker has drawn on about $193 million of that loan, which leaves $336 million yet to tap. The loan actually laid out that Fisker could spend about $169 million on Karma engineering and $359 million on its Project Nina plans.

Fisker spokesman Roger Ormisher told reporters that access to the loan has been blocked since May. Neither party would talk about the renegotiation underway. But DOE spokesman Damien LaVera told Bloomberg that the agency has “strict conditions in place to protect taxpayers. The department only allows the loan to be disbursed as the company meets certain milestones and demonstrates results.”

The DOE’s greentech loan program has come under intense scrutiny since Solyndra declared bankruptcy in October. The thin-film solar module startup landed a $535 million DOE loan in 2009, but looks to be unlikely to be able to pay much of it back. Closer to the automotive industry, lithium-ion battery maker Ener1 filed for bankruptcy protection last month, after receiving a $198 million DOE grant.

Fisker has raised about $850 million in private capital from investors including Kleiner Perkins and A123. That includes $260 million in 2011, most recently with a $150 million round launched in November.

But it’s also struggled to deliver on its $102,000 luxury plug-in Karma, with only 225 vehicles sent to dealers and another 1,200 in the pipeline, CEO Henrik Fisker said in December. At the same time, its DOE loan was made conditional on the company delivering a cheaper mass-market model built in the United States, not by Finnish contract manufacturer Valmet, as today’s Karma models are.

Fisker’s Project Nina plant is also backed by $21 million in Delaware state loans. Fisker bought the site in late 2009, started hiring workers in July and had hired about 100 people as of late 2011. Monday’s layoffs included about 26 Delaware employees and about 40 at its headquarters.

Making cars is expensive, and Fisker must prove it can control those costs as it moves from contract manufacturing collectors' items to building mass-market cars on its own. In that sense, its rival is Tesla Motors and that company's Model S sedan -- but it’s also fighting against auto giants like Nissan, GM and all the rest. Having its first U.S. factory put on hold can’t be reassuring to would-be investors in its hoped-for IPO.