The Supreme Court is getting involved in the longstanding dispute between the Pentagon and two contractors contesting the government's demand for $3 billion over the Navy's ill-fated A-12 Avenger attack plane.

The justices on Tuesday agreed to hear an appeal from the Boeing Co. and General Dynamics Corp., the main contractors on a $4.8 billion project that the Pentagon, then headed by Richard Cheney, canceled in 1991.

The government is seeking repayment of $1.35 billion, plus more than $2.5 billion in accumulated interest, arguing that the companies failed to meet the terms of the contract.

The issue before the court involves the state-secrets privilege, which typically arises in national security and terrorism cases. Invoking the privilege, which the Supreme Court ratified in the 1950s, the government tells a court that allowing a case to go forward would force the disclosure of information that could damage national security.

In this case, the parties are arguing over whether the government's claims about national security have prevented the companies from defending their position that they should not have to repay the money. A federal appeals court sided with the government.

Both Boeing and General Dynamics have disputed the Pentagon's claims that they did not live up to the contract.