Washington - The much-anticipated contract was awarded just before Christmas. BAE Systems trumpeted its victory in a news release and got to work building the Army a new armored vehicle. Finally, one of Pentagon's most intense - and bizarre - contracting wars was over.

Except that now maybe it isn't.

In yet another audacious display of lobbying force, General Dynamics, the giant defense contractor that includes Electric Boat in Groton, Conn., is continuing its fight to win at least a portion of the contract, potentially worth more than $12 billion, to build nearly 3,000 Armored Multi-Purpose Vehicles (AMPV) for the Army.

Contractors often wage fierce, bitter battles for lucrative contracts, especially when years of work and billions of dollars are at stake. But once the contracts are awarded, and any subsequent protests resolved, the loser usually moves on gracefully, not wanting to anger the customer: the federal government.

So General Dynamics' continued attempts to carve out even a partial victory - no matter that the contract has already been awarded - has been seen as a curious, if not quixotic, effort, especially since it never submitted a bid to begin with. But the Falls Church, Va., company, which spent more than $10 million on lobbying last year, according to OpenSecrets.org, has been known as a savvy Washington operator as well as a leading manufacturer of weapons systems for the Pentagon.

Even before the contract was awarded, the company protested to the Army, saying the requirements for the program were rigged in BAE's favor. After the Army denied the protest, General Dynamics took to Capitol Hill, pushing legislative language that could have reopened the competition or forced the Army to buy the company's Stryker vehicles to use for combat medical evacuations.

Now it has taken to the Hill once again, congressional aides say, with an even more creative ploy. A spokeswoman for General Dynamics declined to comment.

The Stryker has wheels. But BAE's vehicle uses tracks, which the Army preferred because it wanted the vehicles to be able to handle the same kinds of terrain as Abrams and Bradley tanks, both of which use tracks.

Still, last month, 31 members of Congress sent then-Defense Secretary Chuck Hagel a letter, urging him to look at wheeled vehicles for the mission, saying they could provide soldiers with traumatic brain injuries a more stable ride.

In the letter, which was first reported by Insidedefense.com, the members write that they "do not seek to encumber the AMPV program. We respectfully request your consideration of the benefits of wheeled medical evacuation vehicles."

The Army has forcefully defended its decision to develop a tracked vehicle, saying that straying from the current plan could cause significant delays and cost - and endanger soldiers' lives.

The medical evacuation variant of the vehicle must have "the same mobility, force protection and survivability" as the other vehicles, Brig. Gen. David Bassett, the program executive officer of the Army's Ground Combat Systems, said in a statement.

Other options, including the Stryker, "would result in force protection and mobility shortfalls that would prevent rapid evacuation and protection of casualties from the point of injury to the next level of care, increasing the risk to our soldiers," he said.

Another Army official, not authorized to speak publicly, said that while brain injuries "remain a critical medical problem for our military," the Army "cannot focus on only one type of casualty at the expense of all others."

BAE Systems said it "is focused on meeting the challenging but essential requirements for the Armored Multi-Purpose Vehicles," Mark Signorelli, the company's vice president and general manager for combat vehicles, said in a statement. "Our team is now working to deliver the required survivability and mobility in a high quality, affordable vehicle. This is the effort that most directly impacts our warfighters, providing them with the vehicles they need and have asked for, on schedule and on budget."